Really shouldn't be a problem.
I don't have a DVD recorder, just a VHS recorder but the process should be the same.
I've 3 scarts on my TV, 2 on my Freeview box, 1 on my DVD player & 2 on my tape recorder.
The set up is as follows:-
. DVD player scart to TV scart.
. Aerial lead into freeview box, then into tape recorder & then to TV.
. 1 scart from freeview box to TV, other to tape recorder input scart.
To record from freeview I set my tape recorder to L1 which is the scart input from freeview box.
If the freeview box has only 1 scart then that's where it gets difficult.