Would using a batch file to perform manipulation of session.ini filenames be of any help as a piece of this puzzle?

FWIW, the following removes the .ini portion (along with double quotes) of a string passed as a first argument to the batch file:

REM based on http://groups.google.com/group/alt.msdos.batch.nt/msg/923423bf3143fcdd
REM try to manipulate first argument to batch file
SET inifilename=%1
REM remove .ini
SET inifilename=%inifilename:.ini=%
REM remove double quotes
SET inifilename=%inifilename:"=%
ECHO %inifilename%

It may be that using double quotes may be important depending on the file path being manipulated.