Changing Sub Spindle C-axis reference point

So, I run a BS32-V and since I have been running this machine the C2 axis has been off by 6.5 degrees exactly when doing work on the back tool post(I will usually just add a g-code to offset the C2-axis for a single program). I was curious as to which parameter changes the C2-axis reference position as I am only able to find the parameter for the main spindle. I would like to permanently offset the c2-axis since it is consistently off by 6.5 degrees.

try with the grid shift parameter

That worked, Thank you