backing sequencer advice

[pinchas]

I am looking and looking and trying and trying to do the following but all to no avail. Perhaps you can't do it afterall...
I made a backing sequence and then saved to the song section. Now I want to record a new section onto the backing sequencer from , say bar 54. Can it be done? If not what can I do? Its hard to record the whole song all at once because its very long.
Please help, anyone?