Hi Rob,
Can you provide some more details on how to create the custom snippet in order to login as the user?
This is the url from that standard button:
javascript:navigateToUrl(%27/servlet/servlet.su?oid=00DE0000000JCDu&retURL=%252F003E0000007weuU&sunetworkid=0DBE00000004CJX&sunetworkuserid=005E00000073EqQ%27);
