Do you mean that you want to express "a;b;;c;;;d" as a list of 7 elements. If so, then the best solution depends on your ColdFusion version. Recent versions take account of missing list elements between delimiters. What is your version?
My version of CF is 9.0.2
In ColdFusion 9, the third argument of the function listToArray, includeEmptyFields, instructs ColdFusion whether or not to include blank list elements. A demo follows:
<cfset list = "a;b;;c;;;d">
<!--- Include blank list elements --->
<cfset array1 = listToArray(list,";",true)>
<cfdump var="#array1#" label="Include blank list elements">
<!--- Exclude blank list elements --->
<cfset array2 = listToArray(list,";",false)>
<cfdump var="#array2#" label="Exclude blank list elements">
Thanks a lot,
I stopped at CF8 doc,
I did not think that old functions have been improved.