need help with audio controls

I have a sound blaster pci 128 sound card. I recently upgraded to windows xp
with sp2 from windows 2000. When I was using windows 2000 with my sound card
controls I had the option in the record controls of looping wav audio back so
that it would seem as if it was comming from a mic feed or something like
that. After I upgraded to windows xp the audio controls changed to the
windows xp controls and that option was removed from the record controls. I
already checked the record control properties and all the available inputs
are checked. there is no longer a wav or stereo input to select. Can anyone
tell me how to get these options back?