Use the IP softphone... most systems have the try buy licenses.
or
You could remote control a PC with a modem connected to it, use hyperterminal to dial the digits.
or
Remote access should be able to do it... but not by dialing a TAC to ride a PRI (as mentioned above)
or
Use Telecommuter to change a coverage path to route externally via your Pri.
or
Program a DID as a VDN, then in the vector route to an outside number with a route to step - that has routing via the PRI in question
or
There's always the security guard....
Hope this helps...
Thanks,
Wildcard