Adding columns to Route and Mark Manager

[PJHoffnet]

Would have to think this has been asked/requested along the line, but a forum search didn't come up with an answer.

- In the Route and Mark Manager (particularly route and track) I'd like to add a column that shows the length of the router/track. While the Properties view for each route/track has that information, along with things like speed and time to complete a route at a specific speed, being able to see that information for several routes in one view would be prefered (at least for me).

Thanks in advance.