I found something about this option (stream from Vmix to BroadCam) and yes, it works !
1. Open Broadcam, start the BroadCam Server (must online and ready to stream) and choose "vmix video" under add device
2. in the same PC, open Vmix and configure Vmix to stream to another server (youtube, etc) and it must be real, not fake address (if you don't want yo stream to youtube you can set up a simple nginx RTMP server in your PC )
3. start to stream in Vmix
4. voila ! it stream into Broadcam too