Distinctive Ring detect in standard PCI telephony fax modem in Dimension XPS Gen2 systems

Unlike Win98 and 2K, for some unfathomable reason Windows XP does not include distinctive ring (two numbers with different rings sharing the same line) handling in its TAPI drivers and can't distinguish between modem response codes Ring1 and Ring2.  However some modems can be setup in the modem itself to recognize and autoanswer on only one out of several incoming ring patterns.  Does the standard modem supplied with the currently shipping Dimension XPS Gen2 systems include this ability or will I need to use an external call director to route inbound calls selectively to the modem or the desk phone based on which ring is present?