And, more importantly, what can I do about it? The code in question (which has been extracted and cut down from the actual code in question to illustrate the problem) is contained in the attached zip file. And the results of running that code are also in the attached zip file. I apologize for the inconvenience that that causes, but when I put the code (important part being %Index[%CharSetInstr[%I,1,%CharSet]]) inline in a CODE section in this posting, it gets "decorated" for reasons I totally don't understand with open and close EMAIL tags. So if you look at the (very simple!) code and the (also vey simple!) resulting output, you will see that the code is completely unable to handle the open parenthesis properly. Frankly, I really don't understand (nor care, when you come right down to it) what the open parenthesis means in these circumstances. I just know that the data that I will ultimately be processing will contain open parenthesis.