Try looking at our MileCharter product:
http://www.mapping-tools.com/milecharter/index.shtml
Add your required locations to MapPoint as pushpins. Then run Milecharter, and it can calculate the distances, travel times, route costs, etc between these locations.
If you want distances from one group of pins to another (eg. depots to customers), then you should put each group in its own pushpinset.
Richard