Creating a route in Basecamp from an Ordnance Survey base map

Hi All

I would be really grateful if you could help me.

I have a Dakota 20 GPS with a 1:25,000 Ordnance Survey (OS) base map of the Yorkshire Dales installed. When I plug the GPS into my laptop and launch Basecamp (BC) I duly see the OS map displayed. Problems start when I try to create a route for a forthcoming hike. BC insists in putting the route along lanes etc rather than across country which is the way I want to go.

Please would someone be able to provide me with a step by step guide to creating a route in BC (either using the route tool or connecting waypoints) that I can tailor exactly to the precise way I want to go. I have watched videos on the subject but they all seem to be based in cities where one would naturally follows streets - my intended route in Yorkshire is much more off road !

Thanks so much and all the best.

Skier01