if you look at which other TV's use the same remote codes on the Sky remote as your Technika then perhaps you can use codes for a different brand.
look up your TV here:
http://www.satcure.com/tech/digicode2.htm#contribthen look what else uses the same number then perhaps you can find the pronto codes for that. Technika is a Tesco brand which is probably the same parts as other brands.
start to build a template, put in the alternate manufacturer and you may find the suggested pronto codes work