Button to rename - then open renamed file with .bat file

Hi.
I have some very handy rename buttons thanks to some guys in this forum, but now I want to build a button which will rename a highlighted file, then take the renamed file and open it with a pre-existing .bat file.

(the .bat file we use at work requires that there be no spaces in the filename used as its input)

How to go about this?

Thanks.

To what exactly do you want to rename it? And what is the name of your batch file?

I want to replace all spaces with underscores (which I already know how to do), then I want to pass the renamed file to

M:/convertmovie.bat

We just can't figure out the command which will feed the new file into the .bat...