Punching in (but not out)

I know about punching in and out but how do you punch in (and not out).  Like the old days with a punch in pedal, reach the point you want to punch in and hit the pedal.  Period.  If I'm one minute into the song, make a mistake, and I want to start from that point.  How do I do it.  I don't want to set an end point, I just want to punch in and continue???
 
Thanks, Kevin