MileCharter can work with individual points or groups of start and end points. Groups of points must be in the form of pushpin sets. You may separate the start and end locations into different groups, by splitting them into different pushpin sets. For example, you could have a pushpin set with pushpins for each of your depots, and a second pushpin set with the pushpins for each of your customers.
Start MileCharter by selecting the MileCharter... option from the Tools menu in MapPoint. This will display a panel that looks like this:
The two listboxes list the pushpin sets that are available. If you wish to add an individual point to these lists, select a location (e.g. a town or city) or pushpin before starting MileCharter. In the above example, there are two pushpin sets defined (Texas Cities and Louisiana Cities), and the city of Carrollton was selected before starting MileCharter.
Select the start and end pushpin sets, before setting the other options.