[Asiaplay]

Your method is correct i.e. search english for the text you want to change and get the language variable name... then open alternative language and find that language variable (and edit / translate the text to your new language and hit the update button) and if it does not exist them add it.
Just one thing - they may not have used lbl... it might be txt_ etc. - so search using "all" (i.e. do not just search labels).

Otherwise.... it might be that the person who did the code for the commercial template - didn't use language variables for the footer text (i.e. hard coded them as text) or that they forget to put lng.lbl_contact_us i.e. forgot to use lng at the front of the variable).

I would check the code for the footer to make sure they have correctly used language variables (e.g. use webmaster mode to identify the file for the footer - open it and check the code... see if it is hard coded... if it is - then change the hard coded text to use language variables.

Cheers - Asiaplay