Any Way To Reduce Low Frequency Volume On A Video

My wife had to record an audition for an upcoming event by KTSY radio here in Boise, but with a single microphone input, there's no easy way to adjust her voice up and the guitar down.  Because the guitar is mostly in the lower frequencies, a graphic equalizer that could be applied to the WMV file below would be useful.

Any suggestions?  It's just an audition tape, so it doesn't have to be perfect, but the guitar is somewhat overwhelming her voice on some songs.

UPDATE: In Ulead Video Studio, there are only very limited audio filtering capabilities, but I split the audio track out from the video, and loaded it into Audacity, which is a rather interesting audio editing tool.  There I applied a high pass filter at 1015 Hz, which took out many of the low frequency (and therefore, high amplitude) parts of the guitar.  Then I amplified the rest by 5.0 db, and while it is not a dramatic change in sound, I do think her voice cuts through the guitar more effectively now.  I'll upload the changes later.

UPDATE 2: Fiddled a bit more: 1500 Hz high pass filter, 6.5 db amplification.  Her voice is definitely cutting through the guitar better, and sounds less muddy to me.  I'll upload the revised video shortly.