I am not so sure about Mapquest, but on Google Maps it's very simple. See the followin URL:
saddr = Starting address
daddr = Destination address
Just plug in your information where applicable. I know when I search on google's site they put + signs where spaces should be, so that may be something you will have to fix. Mapquest probably has something similiar that you can use by inserting the addresses into the URL.
im not sure how your code works.
when i goto Insert, Web Viewer and choose Google Maps (US) and input the fields for Address, City, and Zip........it looks like this:
"http://local.google.com/maps?" & "q=" & /*Address=*/ SUPERVISOR::ADDRESS & "," & /*City=*/ SUPERVISOR::CITY & "," & /*State=*/ "" & "," & /*Zip Code=*/ SUPERVISOR::ZIP & "," & /*Country=*/ ""
There is no place to input the fields for Destination info.
So, I'm not sure how I can manipulate your code to meet mine. I've tried and no go. i will keep pluggin away but hopefully someone posts up a fix.