A possbily easier way than a redirect page would be to set up a campaign to track people who visite from the external source via the "
Visits Webpage" trigger.
Select your page you have them land on as the Web Page to track.
You can then add the constraint of "
Referrer" and then enter your URL in the blank, or if you have multiuple links that you are tracking to the one page, you might want to go the route of Referrer "
Contains".
You can have the smart campaign add these people to a list within the program and you'll have a real-time view of who's visited from that web page.