I am using an SPA525G with a 3CX PBX. Since I let the PBX handle the outbound rules, my dial plan on the phone is very simple: [x*].
I have the 3CX Skype Gateway installed so I can call Skype user IDs. In the phone book on the phone I enter a number as: #skypeID, and in the 3CX outbound rules I simply strip off the #, and that takes care of that. Unfortunately this does not work for Skype IDs that have a dot in the ID. For instance the phone book entry #firstname.lastname always fails with a Network Error. But if I use an underscore instead of a dot, the phone sends #firstname_lastname to the PBX correctly.
The 3CX outbound rules do not provide a way to replace the underscore with a dot. I tried [<_:.>x*]. but that did not work. So the question is: Can I use the phone's dial plan to replace ANY underscore in a number with a dot?