Help me Conect hylafax in PBX

[Amacias Toledo Reyes <atoledo@teran.com.ni>]

Hello folks.

He does one ot two months a person ask of like add a digit automatically 
before, on numbers of fax remote, I remember that becomes in dialrules. 
But doesn't remember the details.

Please if somebody remember as do it, send me the procedure.
In order to connect my modem to PBX.

Very gretefull by their help.

Thank you.