I think the devs overlooked this one when they added the tokenXXX expressions...
How about adding this oversighted findToken expression for finding which position a token is at if it is in the list. 0 is a valid position doing things the C2 way so -1 may need to be used as the "not found" result.
eg 1: findToken("catacombs,cat,catastrophic,triplicate","cat",",") should yield 1
eg 1: findToken("catacombs,cat,catastrophic,triplicate","ata",",") should yield -1