scaling gain~ to match *~

in what way do i scale a gain~ object so that every time it goes up by 1, it goes up by the equivalent of a *~ object going up by 0.01?

so if the gain is set to 50. it is the same as a *~ being at 0.50, if its at 41. its the same as 0.41 on a *~ object.

reason is because i think i did this before, but its on an old broken harddrive that i havent the funds to fix and i need to use volume envelopes without the damn clicking and popping that *~ produces.