There's no string parsing functions other than concatenate available to us.
EQ2Ext adds nice features such as loops and conditionals, but no new functions on the order of splitting strings. (Edit: That I've seen. The version I have is his original, but since he built it from all functions that already exist in the UI builder, I can't see how it would be possible.)
Lol, I suppose we could use loops and concatenate to build the string from scratch, essentially cracking it like a password. Is the con :00B: and the name 'A'? Ok, is the Name 'B'? ...
With the ability to parse about 30 names per second, should only take a couple hours or maybe days (weeks?) to solve and do a /who