I don't think this can be done by Web Service or Command Line.
The only CLI commands for sessions that I know of are these:
/status
/getlog
/requeststop
Technically, /requeststop (as I understand it) is actually changing a session variable, but it is only the variable that is checked by IsStopRequested().
Web Service wouldn't work because web service calls always start up a new session, which would not have access to the session variables of a different session.
I'm guessing that the community-suggested approach would be to try setting the session variable at the database level. I say 'community' because I'm guessing Blue Prism would not encourage this.
Dave Morris, 3Ci at Southern Company