Setting a the PATH from WITHIN visual studio

I'm trying to convert a project build which previously used cumbersome batch files to set up all sorts of environment variables to something simpler.  Visual Studio property sheets seems to have done the trick for most of what I need.  I've got a VSPROPS file I've added to each of my projects that does most of what the batch files did.  Except for one small thing...

Our batch files previously added in a specific folder to the path before launching visual studio.   I would like to at least add this folder into the process path from WITHIN visual studio.  I just want to take whatever %PATH% I'm given and add on my tiny little folder, before I do my build.  That's all.  I tried to use a macro inside the property sheet to do this but couldn't succeed.

Has anyone ever done anything like this?  The whole idea is to NOT have to rely on anything outside of the project.  I want a user to just be able to click on a .SLN or a VCPROJ and have all his paths set for him.  I'm OK with hardcoding them inside the vsprops file if I have to.

-Joe