DVD recorders usually connect via a SCART cable - as presumably you did with your VCR.
There's no "finding a channel" to do - you need to select the SCART input on the DVD. It's usually AV or EXT on the remote.
Having a Spanish TV is neither here nor there as long as you use SCART cables throughout.
SCART from Digibox to TV (from the Digibox TV SCART)
SCART from Digibox to DVD (from the Digibox VCR SCART).
The only problem comes if you want to record Spanish TV from the aerial - then you would also need a Spanish DVD recorder, as the Sound IF frequency is different.