Can I add a suffix to the number dialed when using the client software?

The FaxFinder doesn't have a suffix option, only a prefix option.

Meaning you might ask the FaxFinder to add a 9 before every number if 9 is an access code to dial outside the PBX.
If a 9 is add as a prefix, then all numbers dialed must be outside numbers.

The client phone book may add a suffix to a dialed number, but it would have to be done per entry, it would not be a
global setting. You may also add commas after the dialed number, before the suffix, to add delay between the dialed number
and when the suffix would be sent to the PBX or Telco.