Yesterday Paul provided some help resolving the automatic XP share mounting at system login on OS X. I researched thing a bit further and came up with a pretty good solution with some help from my friend William Dell Wisner.
I created two shell (could/should be Perl as Robin noticed) scripts, one for login mounting the XP share and another one for logout umounting the share. Then I edited the
console "/System/Library/CoreServices/loginwindow.app/Contents/MacOS/loginwindow -LoginHook
This solved the case!