I don't have Virgin, but in general terms you should follow this practice.
1) plug a scart lead from the Virgin box to the DVDR
2) select the external input (eg AV1, AV2 or Ext1 or Ext 2) on the DVD.
3)play something on the Virgin box.
4)Select the DVD on your TV
5) check you can see the Virgin box picture.
If you can, then you can record the Virgin box