Bartosz Wucke wrote:

"I guess with some (a lot of) luck you could tap into some tracks on the card before the PCI target hardware, maybe where the signal is still serial, before all that PCI bus specifities are applied to it. Between the actual -modem- hardware and the -PCI card- hardware.
Of course if these are integrated in one chip, you lose."

All one chip. You lose.

-a