Hi – best way to go about this is to use a custom plugin instead of relying on the theme. I found the following two plugins which may meet your need but I am sure there are many more around in WordPress plugins directory –
http://wordpress.org/plugins/easy-social-icons/ – this one lets you add any social network of your choice. You just provide the URL and the icon (lots of them available on the net through google image search).
Hope this helps.