Pardon me for being blunt but I'm not exactly sure what your asking and since most people arn't good or experience with Multiplayer I'll just try to give you another pair of eyes to help you out.
First from what I understand of multiplayer mechanics the only difference from a singleplayer to its adversary is that you have to update the information between the two. If this is so, your the client and the host are both scanning individually and then sending the equivalent data when needed. So it seems that you could scan a player, and he scan you, but on the local data would be there, any skills and stuff you might need that haven't been updated wouldn't work.
So you scanning the client should work, and he scanning you should work. But I'm guessing the data isn't being sent over the network which is what you are looking for (stop me if I'm wrong).
I'm guessing your problem is perhaps if your getting the client to scan, he's not sending his data to you, in which I might suggest that you use something similar to send_data_to (ENTITY*, void* data,var size) to get the data sent to your computer that you need based on his scan.
I'm going based of the theory that you can scan, your client can scan, but you can't scan for your client. Just a collection of thoughts, you might want to elaborate if you want more help on the extent of your problem (what your trying to retrieve, and from where)
