I believe, livechat option is all about adding JS code. In this case, please check the mod I wrote for fixh as an example:
http://forum.x-cart.com/showpost.php?p=370131&postcount=10
Besides that, the following article will be helpful for you as well:
kb.x-cart.com/display/XDD/How+to+insert+your+HTML+code+into+any+part+of+the+ page