[GRASSLIST:3957] Creating Polygon vectors

Hi

I have GPS data (GarminII) in Waypoint+ .txt format (saved as tracks). I also 
have an imported vector (,shp) file with the outer boundaries of the whole area 
of interest (a Game Park). I want to create polygons from a combination of the 
park boundary and the GPS tracks. Is there any documentation about how to go 
about this?

Thanks
Chavoux