how to set an environment variable from within a makefile

[Mark Galeck (CW)]

Hello,

The export directive can be used to communicate variables to sub-makes.

Is there a way to communicate a variable up-stream, or between makefiles in the 
same depth of recursion.  I thought I would try to setup an environment 
variable from within a makefile,
either using
                FOOBAR=value
in a recipe,
or $(shell FOOBAR=value) , outside one.

But this does not seem to work - it only works in the context of that same 
makefile, but not outside of it,

How can I do this through environment variables?

(I can probably use writing to a file to store that information, but I would 
rather use env variables).


I somehow suspect this is a stupid question.  Oh well, let Paul & others laugh 
at my naivety.

Mark