The other thing is that I don't want to use the existing <%Title%> to display the link. I want to use a separate value so the displayed title isn't affected.

You can see an example of how I'm currently doing this here.

My format is:

<%Title%> = Manufacturer
<%URL%> = Product Number (internally linked)

then

<%Website%> = Would be the separate link the the manufacturer.

Hope this makes it a little clearer.