How can I get the file version for a .sln, if possible?

[ambalboa]

How can I retrieve the version number from an .sln file which I'm using to build with a 'Make VS.NET' action step? I also tried to get the number from an .msi file, which is created by the action, but nothing. I know how to do this for an .dll file, and this approach gives me no errors but no number as well.

I want to know what that number is to be able to increment it and set it to that value. Is there some other file that I should be looking for?