MOTM

Does anyone know of a simple way I could add a DC offset or adjust the
tracking/scaling of a resistor chain keyboard? I want to be able to use
this keyboard with my motm gear but I would still like to have the
modules calibrated to my Encore Expressionist. I know I could calibrate
to the resistor chain keyboard and then use the Encore to set the
offset/tracking, but there's something wonderful about being able set
the encore at 0/0 and have everything in tune. (It just seems
blasphemous the knock everything out of calibration to use this silly
keyboard) Any suggestions? Simple circuits? Schematics? Let me know.
Thanks -Nate