Using a Broadband card to dial a remote modem on phone line

My customer's laptop has USB Broadband card. It is installed as a modem in Device Manager and I am using COM 6. I am trying to make it dial directly to a modem at another location which is on a standard POTS line. Application here is similar to remote dial-up between two PC's with PCAnywhere.

I have done this successfully before but cannot get this Broadband modem to dial out. It does, however, connect to the Internet. Why would some Broadband card dial a phone number and others not? I realize that most people use their broadband card for Internet connections and not to dial a specific number. Again, I have been able to do this at many locations without problem.

What issues can I look at to make this work? Do I need a particular bradband service? Currently, this service is a 5Gb maximum per month and is $59.95

Any help is greatly appreciated !!!!!!!

Baffled in Maryland.