You have a current network, and you want to add an additional show. Here are the steps.
Login to Podpage
Click Podcasts in the bottom left corner of the screen.
Click Edit Network Shows near the top
Click New Show in the upper right hand corner.
From here you can search for the show, or copy and paste their RSS feed.
After adding the show you can click the Go to dashboard link at the bottom to return to your dashboard.