this recent topic shows how to connect via IP, i suggest you try this? http://discoverygc.com/forums/index.php?showtopic=44595
if you get kicked instantly for cheating or similar, take the global server workaround off and try again, discovery needs and unpatched version of freelancer or it may kick you thinking you have a another mod in use
Tried both manually typing the parameter and directip exe that does that for you, with no luck.