if you can't unscrew it from the antenna, you can get another length of cable and a F/F connector like this one to tie them together:
http://www.amazon.com/F-Pin-Coupler-.../dp/B000I991LM
http://www.amazon.com/Performance-Se.../dp/B000N7HT86
Nothing magical about Amazon, you should be able to find these locally at RadioShack, Fry's, or even HomeDepot.
by line of sight, if you stand where the antenna is and face that window, what direction are you facing?