MOTM

Ok.

Don't laugh, but I am seriously a circuit goon.  I have this thing that I 
am building, and I am doing some funky stuff with voltages.  I find I need 
to be able to generate a differential voltage based on a pot.  For example:

I have a 2.5V input to this circuit.  When the pot is fully CCW (0) puts 
out 2.5V on 2 separate lines,  when it is fully CW (10) it puts out 2.2V 
and 2.8V on 2 separate lines.

I am sure this is a fairly common circuit type, but to learn about it, it 
would seem I need to know its name (all the schematics in the books are 
listed by common name, not function).  Could someone name that circuit?

Thanks

Bruce