CATV to S-Video

While this may well not be the correct board for this question, I'm not sure where else I should put such a query.

Basically I want to know if it is possible (and if such a product exists) that will allow me to convert from a standard CATV cable format to S-Video format.

CATV is the format used for standard television cables in the UK (and possibly elsewhere) consisting of a round outer ring about 8mm wide with a single metal point in the middle about 2mm wide (or an inner circle to acept that point for female connections).

I need this because my TV Card will not accept standard TV connections and so I assume there must be a way to do this - otherwise the TV Card is surely useless.

http://store.yahoo.com/technicalconnectionsinc/sad.html

Ah by the looks of that page, I will have to go adapater->adapter->adapter before I get what I want...
grrr...

Thanks.