Perhaps you could be a little clearer on what it is you want, I for one havn't a fuckin' clue what it is your asking here. Welcome to the HoL. :wavey:
I think they are asking how to do things in multiplayer. The easiest way to form a party in multiplayer is stand close to each other and have one person type "#join" in the local dialogue screen, this is green letters that you see on the screen not the private chat. As far as trading goes you'll just have to put items in a trashcan or on the ground and have the other person pick them up. PC to PC interaction is pretty limited in multiplayer, I think that part was rushed out to make the deadline.
Hi, welcome aboard. You can export a PC to multiplayer & carry along anything she has in her inventory, & get it to another player's PC in multiplayer. You can't bring it back to a solo game though. Is that the answer to your question?