Hi Danny,
There isn't a really quick way to do it, but what you could try is group-selecting all of the tracks you want (in the asset list), then right-click and export as CSV/GPX, then reimport this single track. Once you have a single track with all of the tp's you need, you can just region-select the area you want and choose Crop to range. Yo'll then be left with a single track containing track-points only within your selected area, and you can export this to CSV.
