i've not tried it in ApexDC++, but i guess there must be a column like "IP". actually, when receiving search requests, you only receive IPs, and ApexDC++ can't have an easy way to match this IP to someone's nick. however, once you have established a connection with this IP (i mean, download his file list for instance), ApexDC++ can then know this user's IP. try it and see if it works, otherwise IIRC it needs few work in ClientManager.