Audio Trim

Greetings from Downunder
In PPT 2010 we have (at long last) the ability to trim, fade in and fade out
audio tracks. I have a track that needs the first 7 secs to be removed and I
can overcome this by advancing the green slider to the right. But that 7
secs of audio is still there, just not being played. My question is -- can
that 7 secs be REMOVED from the audio timeline permamently.
All help always appreciated.