I have never used Tk, but I have used Win32::GUI. It's been a while since I have used Win32::GUI, but I thought that there was something in the module related to this.
The Win32::GUI tutorial part 9 discusses this issue. It covers what needs to be done to perl.exe and that ActiveState Perl has a perlw.exe executable with this modification. In Strawberry Perl, I see a wperl.exe, which could be the equivalent of ActiveState's perlw.exe.
Combining the above information, it might be possible to modify pp to use wperl.exe instead of perl.exe to bundle your code into an executable without the console window.