Hmm...because the Blitz files are in ASCII, you could just go through each line like a regular file, and whenever it finds a certain function (i.e. LoadMesh), it can locate the string's beginning and end with Instr, and then Replace LoadMesh("whatever") with LoadMesh(TrackFile("whatever")). Perhaps that would work, and it'd run through your whole program.
Hope this helps.
Hope this helps.