INF input parameters/read environment variables

Is it possible to pass information into a driver installation process? I
ask since my inf file also installs some supporting services along with my
driver. I would like to put the binaries for those services into a
user-chosen directory in Program Files. But to do that, I need to be able
to communicate from my installer to some sort of place-holder in my inf
file.

Is it possible to specify that an inf file should read a string from the
environment?

Is there any other way to be able to parameterize driver installation?

Regards,
Joe.