Firstly if your using a 4 digit internal extension number for the phones, I would consider changing that to either 3 or 5 digits as this will complicate things.
I would then forget about using a wildcard if your going to control these 4 digit numbers through the IPPBX Dial Plan digitmap and not individually on the actual phones digitmap.
Then you can either prefix the IPPBX with a single digit (the most common way of doing this is by using 9. Most standard telephone systems require the use of dialing 9 to access an outside line, even BT does this on their featureline product) and force all calls prefixed with 9 containing a min length of 5 digits to be stripped of the 9 by adding the 9 OP number and to route only to the ISDN1-TE or ISDN2-TE (i would use ISDN2-TE as the ISDN1-TE port has a known fault) Please note if using 9 that you might need to accomodate another digit map to call the emergency services e.g 999. You would then need to inform the users that if they want an outside ISDN line they have to dial 9 first.
Or you can just set the digitmap to look for min/max 4 digits with no prefix or OP number and tell it to route these over ISDN.
There is also the option of programming the 4 digit numbers in the phone book or speed dial.
Hope this helps
Lee
