Ok...just looked that up. Off to ebay I go...

INPA is a diagnostic interpreter program that communicates with your car using BMW's own factory developed Electronic Diagnosis and Information protocol (EDIABAS). INPA is a powerful and comprehensive diagnostic tool but there is no simple handbook available that I know of which will comprehensively explain its operation or functions. The bottom line with INPA is if you do not understand what a particular function does, you are probably better off leaving that function alone, but having said that, the level of diagnostic functionality is truly exceptional.