I'm afraid there isn't anything I can do in this case. Once I call out to the RCOS to move the focuser, and that call does not return, by the rules/behavior of Windows inter-process LPC, the calling process is in "suspended" state. As you can see it will not respond to any stimulus. I'm sorry to seem heartless or uncaring.... But this sort of bug cannot be overcome by another program. See this (reposted) 2013 post on the general problem, I had to write this to prevent me from repeatedly explaining the general problem of ACP being a "software victory over others' bugs" package.

Why is it that ACP gets "stuck" sometimes? Can't you do something?