There is no out of the box cpl, but feel free to write some endpoint source based mapping your self.
If its fine for you to have one common "prefix" then you could also add that prefix in your search rule,
so instead of dialing a one digit prefix you have to dial 02344523 or something like that.
Also check out if you could register your systems directly to cucm or if you could do some handling
of the access code on the gw or your cucm