Depends on what kind of 'looks' you want to change, can you describe it in details ? Also are you new to C++, windows programming ?
You mean you want to add more buttons in IE's toolbar ? Or you want to change ones which are already there ?
Internet Explorer Toolbar (Deskband) Tutorial - The Code Project - ATL
Toolband (Toolbar for IE) sample using WTL - The Code Project - WTL