ForceCommand not working, or how to force a client into a different shell

"OpenSSH for Windows" version

 PS C:\Program Files\OpenSSH> ((Get-Item (Get-Command sshd).Source).VersionInfo.FileVersion)
Get-Command : The term 'sshd' is not recognized as the name of a cmdlet, function, script file, or operable program.
...

It's v7.6.0.0p1-Beta though

Server OperatingSystem

((Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows nt\CurrentVersion\" -Name ProductName).ProductName)
Windows Server 2012 Standard Evaluation

Client OperatingSystem
PuTTY on Windows 10

What is failing
Cannot get the client to go straight into any other commands or shells.
In C:\ProgramData\ssh\sshd_config:

Match User domainadmin
ForceCommand python

In C:\Users\domainadmin\.ssh\rc:

python

/etc/passwd does not exist in windows.

Expected output

Python 2.7.14 (v2.7.14:84471935ed, Sep 16 2017, 20:25:58) [MSC v.1500 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>

Actual output

domainadmin@mydomain@servername C:\Users\domainadmin>

I know the match block is working because if I put PasswordAuthentication no in there, it rejects domainadmin from logging on. I would try changing DefaultShell in the registry, but that is in HKLM and I only want it to be for one user, and adding DefaultShell to HKCU\SOFTWARE\OpenSSH had no effect.

Maybe I'm barking up the wrong tree here. I have an interactive python script that needs to be run as admin on the server over SSH, but I don't want the end user terminal to have access to an admin command prompt. My plan is to force the SSH connection to go straight into python c:\path\to\script.py and make sure the connection terminates when python completes. On Linux, I would just need to change the user's shell in /etc/passwd to /usr/bin/python /path/to/script.py, but in this case it needs to run on the Windows server. What am I doing wrong or how can I make this work?