As Ethel says, you need a DVD recorder.
Also, you say the tapes are specialised. If they are bought tapes that MAY mean they are copy protected.
If they are ordinairy "home" tapes done off the TV or copied from a video camera you will be OK.
I copy VHS tapes to DVD all the time.
I connect my VHS player to my DVD recorder with a scart lead, "play" a tape in the VHS machine while recording a DVD in the DVD recorder.
The DVD makes a copy of whatever is playing in the VHS player.