How to make a "dynamic" Perforce Client Spec

[Conrad Weyns]

I am new to VBP. After 30 minutes use, I passed the point of no return :-)
The first step in my .bld is the "Perforce" tool for retrieving the latet version of a large devstudio solution.
There was no problem getting this to work.
Now I'd like to try something more advanced and share this .bld file through the Perforce depot.
This means I need to figure out a way to make a cleaver Perforce step where the local path og the .bld file somehow gets mapped to "a" or "the" correct Perforce Client Spec.
Of the 4 parameters in the Global Options, only the Port is static. The Client, Host and User need to be dynamic.
Has anyone attempted this or something similar? Any recommendations?
Conrad Weyns