If your local CO sends your DID's to you through your DNIS trunk, then as stated above, simply use the command - DIS DNIS - and the incoming digits, and where they are pointed to (the final extension) will be listed. If using Windowss-based EMML, make sure to click on the "output" pulldown menu and create a file in your C-drive so that you can print the file. If you aren't using the Windows-based EMML, then press the appropriate F-key to turn on the print function.
If your DID's come to you through a set range of numbers to Your PBX through incomming trunks, you can call your CO (AT&T, Century Tell, etc.) and request a list of your DID numbers according to your billing address.
Good luck.
Seeeeeya; Goodweed of the North