In Call Routing there is a DID Translation Table... that is how I do ALL of my system now days, 10 digits in, no absorb, and it merges with the User & Device form so you can set the DID and outbound Caller ID with no issues from one form.
It is fairly simple to change it as well, just export the system speed dial and DID Translation table forms, copy and paste appropriately, and import the DID form, turn on the DID translation table in the Trunk Service form, test, and delete the range from System Speed Call.