Line-In using external Microphones for broadcast via Ustream

Hello

I have a question about your app. I would like to plug in an external microphone to broadcast via Ustream.
Or, better yet, broadcast using the line out from my digital recorder.

I have tried to accomplish that with your app. When I plug in the line out from my recorder, Soundabout recognizes it as a microphone, which is great.
I also manually set Media Audio on your app to Wired Headset with Mic. However, it still picks up only the phones microphone when using Ustream.

Does this sound like something I could accomplish with your app?
Am I doing something wrong?

Thank you  

If you are using the app for Ustream, the Ustream app could be controlling the audio in/out settings. Are there any settings you can see in that app?