There's no need to hack the code. Simply create a delimiter field within Field Management and add it to your userlist. The contents of the delimiter as follows.

[code:1]
<a href="index.php?option=com_comprofiler&act=connections&task=addConnection&connectionid=[user_id]">Add Connection</a>
[/code:1]

Please note this won't be conditional though. It won't hide if a connection had already been made. For that you'd need to develop something a bit more complex or edit the CB template PHP file and add the code to handle connections directly to the users row.