OK, incoming aerial is to VCR, then connected to TV via aerial lead/coax socket, correct?
Have you a SCART socket on your TV? What you need is a Scart to phono converter. Basically, it's a Scart plug with three phono sockets on the back of it - Audio Left, Audio Right & Video.
You need a two x phono plug to 3.5mm stereo jack lead to transfer sound. The two phono plugs go into the Scart/Phono converter, 3.5mm jack goes into line-in on sound card. It should work on either the TV or VCR.
tbh, I'm not entirely sure that would work, I've never tried to record TV programmes, but when I record from VCR, I switch it to AV channel 1 or two, then both audio and video are outputted through Scart socket.
Scuse me, I've been down the pub a while, will have to think about this
You
will need that Scart/phono lead converter & associated leads though, unless TV or VCR has phono sockets, in which case no converter required, just use phono leads.