Text Link Ads (php to call xml within tpl file)

I'm trying to get Text Link Ads (tla) working on my site, but I can't seem to do it properly.

I tried to use the smarty {php} and {literal} functions but the script still doesn't seem to take.

Basically, there is PHP code which needs to be inserted within the index.tpl file, and that code is designed to call another file that I put on my server (chmod 777) to pull the ads from the remote TLA server.

Can anyone point me in the right direction for this?