diff --git a/R/CellCounts.R b/R/CellCounts.R
index 429981a..6499eb9 100644
--- a/R/CellCounts.R
+++ b/R/CellCounts.R
@@ -75,12 +75,61 @@ CellCounts.COMPASSContainer <- function(data, combinations) {
 
 .CellCounts_character <- function(data, combinations) {
   
+  ## Pre-parse the combinations by expanding entries of the form
+  ## "A*B*C" to
+  ##
+  ## A & B & C
+  ## A & B & !C
+  ## A & !B & C
+  ## ...
+  ##
+  ## TODO: Handle things like A&(B*C)
+  combos <- lapply(combinations, function(x) {
+    
+    ## Bail if no '*'
+    if (!grepl("*", x, fixed=TRUE)) return(x)
+    
+    ## Bail if unsupported combination seen
+    if (grepl("*", x, fixed=TRUE) && grepl("[&|]", x, perl=TRUE)) {
+      stop("currently cannot combine '*' expander with '&' or '|'",
+        call.=FALSE)
+    }
+    
+    ## Generate a matrix of 0s and 1s that forms the same 'structure'
+    splat <- unlist(strsplit(x, "*", fixed = TRUE))
+    n <- length(splat)
+    values <- do.call( 
+      function(...) {
+        expand.grid(..., KEEP.OUT.ATTRS = FALSE)
+      },
+      replicate(n, c(0, 1), simplify = FALSE)
+    )
+    
+    ## Replace the 0s and 1s with appropriate names
+    for (i in seq_along(values)) {
+      values[, i] <- swap(values[, i],
+        c(0, 1),
+        c(splat[i], paste0("!", splat[i]))
+      )
+    }
+    
+    ## Paste and return the output
+    do.call(
+      function(...) paste(..., sep = "&"),
+      values,
+      
+    )
+    
+  })
+  
+  combos <- unlist(combos)
+  
   output <- .Call(C_COMPASS_CellCounts_character, 
     data, 
-    lapply(combinations, function(x) parse(text=x))
+    lapply(combos, function(x) parse(text=x))
   )
   rownames(output) <- names(data)
-  colnames(output) <- unlist(combinations)
+  colnames(output) <- combos
   return(output)
 }
 
diff --git a/src/RcppExports.cpp b/src/RcppExports.cpp
index b27545b..290e943 100644
--- a/src/RcppExports.cpp
+++ b/src/RcppExports.cpp
@@ -5,32 +5,32 @@
 
 using namespace Rcpp;
 
-// CellCounts
-IntegerMatrix CellCounts(List x, List combos);
-RcppExport SEXP COMPASS_CellCounts(SEXP xSEXP, SEXP combosSEXP) {
+// CellCounts_character
+IntegerMatrix CellCounts_character(List data, List combinations);
+RcppExport SEXP COMPASS_CellCounts_character(SEXP dataSEXP, SEXP combinationsSEXP) {
 BEGIN_RCPP
     SEXP __sexp_result;
     {
         Rcpp::RNGScope __rngScope;
-        Rcpp::traits::input_parameter< List >::type x(xSEXP );
-        Rcpp::traits::input_parameter< List >::type combos(combosSEXP );
-        IntegerMatrix __result = CellCounts(x, combos);
+        Rcpp::traits::input_parameter< List >::type data(dataSEXP );
+        Rcpp::traits::input_parameter< List >::type combinations(combinationsSEXP );
+        IntegerMatrix __result = CellCounts_character(data, combinations);
         PROTECT(__sexp_result = Rcpp::wrap(__result));
     }
     UNPROTECT(1);
     return __sexp_result;
 END_RCPP
 }
-// CellCounts_character
-IntegerMatrix CellCounts_character(List data, List combinations);
-RcppExport SEXP COMPASS_CellCounts_character(SEXP dataSEXP, SEXP combinationsSEXP) {
+// CellCounts
+IntegerMatrix CellCounts(List x, List combos);
+RcppExport SEXP COMPASS_CellCounts(SEXP xSEXP, SEXP combosSEXP) {
 BEGIN_RCPP
     SEXP __sexp_result;
     {
         Rcpp::RNGScope __rngScope;
-        Rcpp::traits::input_parameter< List >::type data(dataSEXP );
-        Rcpp::traits::input_parameter< List >::type combinations(combinationsSEXP );
-        IntegerMatrix __result = CellCounts_character(data, combinations);
+        Rcpp::traits::input_parameter< List >::type x(xSEXP );
+        Rcpp::traits::input_parameter< List >::type combos(combosSEXP );
+        IntegerMatrix __result = CellCounts(x, combos);
         PROTECT(__sexp_result = Rcpp::wrap(__result));
     }
     UNPROTECT(1);
diff --git a/tests/testthat/test-CellCounts.R b/tests/testthat/test-CellCounts.R
index 6a59f77..633381d 100644
--- a/tests/testthat/test-CellCounts.R
+++ b/tests/testthat/test-CellCounts.R
@@ -15,23 +15,40 @@ data <- lapply(data, function(x) {
   return (x)
 })
 combinations <- colnames(data[[1]]) ## [1] "A" "B" "C" "D" "E" "F"
-expect_identical(
-  CellCounts(data, combinations),
-  CellCounts(data, 1:6)
-)
 
-expect_identical(
-  CellCounts(data, list(c(1, 2, 3))),
-  CellCounts(data, list("A&B&C"))
-)
+test_that("The integer and character interfaces for CellCounts match up", {
 
-y <- "A&B&C"
-expect_identical(
-  CellCounts(data, list(c(1, 2, 3))),
-  CellCounts(data, list(y))
-)
+  expect_identical(
+    CellCounts(data, combinations),
+    CellCounts(data, 1:6)
+  )
+  
+  expect_identical(
+    CellCounts(data, list(c(1, 2, 3))),
+    CellCounts(data, list("A&B&C"))
+  )
+  
+  y <- "A&B&C"
+  expect_identical(
+    CellCounts(data, list(c(1, 2, 3))),
+    CellCounts(data, list(y))
+  )
+  
+  expect_identical(
+    CellCounts(data, 1:6),
+    marginal_counts(data)
+  )
+  
+})
 
-expect_identical(
-  CellCounts(data, 1:6),
-  marginal_counts(data)
-)
+test_that("We properly expand with a '*' in the name", {
+  
+  expect_identical(
+    CellCounts(data, "A*B"),
+    CellCounts(data, c("A&B", "!A&B", "A&!B", "!A&!B"))
+  )
+  
+  ## TODO: allow combinations of * and [&|]
+  expect_error( CellCounts(data, "A*B&C"))
+  
+})