Ah, now I got your suggestion. I was mistakenly thinking of our powershell support we have for Royal TS and Royal Server.
We will check this internally - thanks for the suggestion!
RoyalTS.exe /RoyalServerDocument MyRoyalServer:MyRoyalServerDoc
I am still not sure what you want to achieve.
As for the commandline, we ave several options here:
(including opening a file in an already running royalts instance)
Let me know if this helps,
what do you want to achieve with this doc? Usually its opened in Royal TS/X and the user can then execute connections/tasks/etc