Hi, first of all if the CM is only one, you don't need to send to different addresses, you can strip digits easily with a translation-profile at voice-port level.
But if there were two CMS and a single GW, you could use two techniques, cor and "steering digits" Both have separate incoming DP based on "incoming called-number". With COR, you distinguish which DP outgoing to use, based on COR settings. With "steering digits", the incoming DP adds a certain number to match an outgoing DP, tha number is the stripped out via translation-profile.