VB6 and TAPI? / reading from another window

Hey Guys,

I have a small problem going on. Basically i need to code a program to work with (sort of) a client's PBX system. They're running a Zultys MX250 that has something called Call Attached Data. Bascally when a caller calls in, they punch in their 5 digit account code, and the code shows up in the PBX software.

What they're looking for, is that the account window should open automatically in their CRM when that call comes in. I already have coded the account lookup and launching the account window based off the number, I also have my vb project already set to run from system tray full time without being in the way. What I need is for a way my program can 'read' the account code from the PBX program. From my research and what I've seen I can do this by either 'reading' the little notification pop-up on the screen that occurs when a call comes in, and parsing the account code from that window (not quite sure if this is even possible, depending on the PBX Software) or by using TAPI, the pbx does have a tapi driver that will be installed on every client machine. I've never coded anything tapi related before and I'm completely lost. Any help would be appreciated.

Thanks,

MendyGreen