where to replace link in html code

yes i have html code that i copy and paste into a program that? i have .. i know where to replace link so i can put in a domain of mine that redirects to theirs. But what i am trying to do is put in a link that i know works into the adds that i market.. What the link does is track the clients that open the email that i send them. This is all i need and some advise on some brife html questions. Thanks , Ryan executiveleads@[login to view URL]