No "shift" button per se, but several possibilities
A "transpose" knob has the same effect on Ccs as it does on notes, so you can change a Cc number up or down as desired. The "shift" button would move the "transpose" knob between two desired settings.
Use show/hide panels. When the shift button is pressed, it replaces one panel & controls with the "shifted" values
Advanced - use StreamByter to capture the shift command, and perform arbitrary transformations on the desired control outputs.