Perfect. Thanks for the quick response. Now that I understand how it works I see that escaping the backquotes will let me pass spaces in any parameter, not just not just the last one.

I'm not sure if this is a bug or WAD, but it appears that backquoted parameter strings passed to subroutines do not get treated as a single parameter with embedded spaces as they do when calling a separate batch/btm file. I was able to get around the issue by making the last parameter for the...