use media player

[Pace]

is there a plugin that lets this use a media player (ie. winamp) as the aux. source ?

[xoas]

Speaking of Winamp, there is a codec which allows the dMC (dBpowerAMP Music Converter) to read (and therefore convert) files recognized by Winamp plug-ins but for which you do not dMC codecs. This is available through Codec Central as the Winamp Plug-in Adaptor here:
http://www.dbpoweramp.com/codec-central-winamp.htm
This may not work with all Winamp plug-ins.

dMC also has an Auxilary Input funtion that will let you record from a variety of sources including your soundcard. More on this use of auxilary input can be found here:
http://forum.dbpoweramp.com/showthread.php?t=5362

dMC does feature a variety of codecs which would allow you to convert files to different formats also available through codec central.

Hope this helps.
Best wishes,
Bill Mikkelsen