Yes, this is so possible. the cmd to pop up the class/clantag text editer is used in a-lot of infectable mod menus. I tryed a r2r menu and the cmd was used to edit dvars like jumpheight and say msgs. I'm not extremely good at coding but I've only tryed it with activeAction, I haven't seen any scripting for the in-game keyboard in the patch. But i'm sure you could possibly find something in the code_post_gfx_mp.ff from the game iso as the majority of lobby functions are found here.