Change Links In Sub Frame?

not entirely sure this is possible but I have a site people (owners) to use in the shop. I need to make a public accessible side using the same layout. I decided frames would work for this calling content in sub frame. The problem is 2 of the links in the content sub frame contain sensitive information. I cannot change the content or it will affect lots of other users. I cannot edit the content as it affects too many people. It does not reside on the same server.

So I need to change what happens when 2 of the links are clicked. I know the urls, can I force, maybe using code embedded in the top frame, to make 2 links go somewhere else. I.e page loads 2 frames, one is header, other is content.

If customer clicks "trade-prices.html" in the content frame they are taken somewhere else (of my choice) by code sitting in parent to prevent them seeing it. I need to prevent 2 links from opening, or force them to open another page/substitute if > then scenario would be ideal e.g if url trade-price.html link is clicked/loaded then redirect to