This is doable with just CSS alone.
Assign the social network links as normal menu items, then view source to get the id ( and/or class ) specific for that item, then style these links as needed.
Starting with float: right
and then some padding-left
just enough to fit the social icon, and then assign the icon as background image, also the text-indent:-9000px
to hide the text itself.
There you have socialmedia links within the nav bar floating to the right.