Just found out that it is really easy to do this, previous attempts with run-process had issues with the prompt.
Just call
(run-python "z:/_pipeline/shotgun_config/btltest/tank.bat shell")
Or with a prefix argument C-u M-x run-python and then enter z:/_pipeline/shotgun_config/btltest/tank.bat shell
Credit goes here How to customize run-python function? - Emacs Stack Exchange