Newbie question about auto recording

[RFrecordings]

Let's say I messed up playing guitar on a track, but don't want to just waste the 2 minutes of good track before that. How can I set a marker right before the part I messed up at, so I can play along with the track as it goes, and then once it hits that marker, it starts recording, thus overwriting the messed up part?

 

[seismetr0n]

what are you recording on? .. sounds like a tape machine
many reel-2-reels will have a punch in footswitch or button... have someone push it for you while you play along..

gl