Redirect from home?

Some users would prefer to skip the home page and go directly to their data entry form. I can setup a preference form that allows them to pick a page, but where can you put the code that changes the target page? In the default.aspx I direct them to the home page(which is attached to a master that has the login link. Just to test it I added a redirect to the page_open of the home page, with the second argument = true. (I think that should stop processing the current age, and follow the redirect)
My mistake, I was using the wrong target page which errored. But the problem now is that if you put the redirect in the   home page open it will always redirect and you can never get to the home page, Is there  somewhere you can put the redirect so it only does it once?