VB 2008 Express Replace string inside of Javascript on page loaded into axWebBrowser

Question

I am using VB 2008 express and would like to know

If i can Replace a string inside of Javascript on page loaded into axWebBrowser so i can then execScript that function.

The specific string i wish to replace is "_new" to "_self" this is so when i call the function it will load in the same page instead of poping into a new web browser.

Also, is there a way I can just insert my own javascript function in the DOM as well?

Either solution will help me to acheive my goal.

Thank you in advance for looking, Ernie