It's possible and works the same way on the emulator as one the phone.
All you need to do is open your connection (MFStandardConnection or NDEFConnection)with
Then you can use the internal tag as you'd use an external one.
In the emulator, you'll have to attach the simulated tag to the "internal Mifare" slot. You might also need to edit the preferences (tools>preferences) in order to change the security domain to "maximum" (in the MIDP tab).