Create an InputField, grab examples from text-based Wogw or any NPC options you've got that allow input.
So, I'd send an interface + inputfield... might not be the best way to do it since I am not great with interfaces n stuff... but works for me.
Example can be taken from my NPC Droptable Search function
Code:addInputField(39806, 30, 0xFF981F, "NPC/Item Name..", 130, 28, false, false, "[A-Za-z0-9 .,]");
Server
Code:case 39806: Server.getDropManager().search(player, text); break;