Yes, this should be possible. The tag file (.vtg) for your source code is stored in the same directory as your workspace (.vpw) file. The tag files for your libraries are stored in your config directory, in a subdirectory named "tagfiles".
If I understand your goal, you want to move the same source files and configuration around but have different library tag files for the compiler libraries. Correct?
The easiest approach might be to create a tagfiles32 directory and a tagfiles64 directory and then rename the appropriate one to tagfiles when you launch SlickEdit. You could easily write a script to do the rename and then invoke "vs ...".
To create these directories, start with an empty tagfiles directory and tag your libraries on the 32-bit machine. Then copy those files to the tagfiles32 directory. Do the same thing on the 64-bit machine, but copy those tag files to the tagfiles64 directory. Those files don't need to be updated until you add/remove a library or upgrade your compiler. When that happens, copy the updated tag files back to the appropriate 32/64 directory.
I can't tell from your email if you're running SlickEdit from your USB drive or not. That works very well, and we've given out trial versions of SlickEdit preinstalled on USB drives at conventions. You can even store and use the config locally, on the USB drive, using the -sc option to tell SlickEdit where to find the config.
I have attached the autorun.inf file we use to automatically launch SlickEdit when the USB drive is inserted. There is also a vs.bat file to launch SlickEdit from the command line. The readme.txt file explains a bit about how things are set up.
Note, these were taken from a drive where both the Windows and Linux versions were installed. So, the drive contains a subdirectory for each. You may want to take the "windows" subdirectory out of the paths in those files and just have a "SlickEdit2009", or whatever you prefer to call it, directory. You can modify them to rename the tagfiles directory. Perhaps you could test for hostname and do the rename based on that.
I'd be interested in hearing if anyone else has a better suggestion for how to accomplish this.