is there a way to launch N++ with compare with two files as arguments?

like:
notepad++.exe --compare a.txt b.txt

The reason is so I can use it with perforce. Araxis Merge has something similar, which is:
compare.exe a.txt b.txt

(which is very nice because I can call "p4 set P4DIFF=compare.exe" and everything magically works)

I agree, that would be very useful. But afaik notepad++ itself doesn't support custom commandline options for plugins. It would always ask to create the file '-compare'…

I need this so much too.  So, why not at once allow plugin command line parameters?
How does one make a feature request for this?

I also this feature, I could use this compare plaugin with Visual Studio instead of Source Safe compare