[Plugin: WP No External Links] Nofollow in Custom fields

I have a wordpress network. All the contents in my network are user generated. All posts links are now dofollow. I want to change it to nofollow. My site uses plugin for custom fields. I removed the default description area. So i cannot use the_content function. I use custom fields for all.

I tried many auto nofollow plugins including wp-noexternallinks . But its not working in my custom fields ( I use magic fields plugin for custom fields) . Can anyone help me?

Is there any function code available?

I just want

My Link
to

My Link
Thanks

http://wordpress.org/extend/plugins/wp-noexternallinks/