why not just have the install.msi in a shared path.
then at startup, run something like:
(and (or (not (findfile "C:\\Program Files\\Common Files\\OpenDCL\\OpenDCL.18.arx"))
(not (member "OpenDCL.18.arx" (arx)))
) ;_ or
(findfile "OpenDCL.Runtime.ENU.6.0.0.1.msi")
(command "_.start" "OpenDCL.Runtime.ENU.6.0.0.1.msi")
) ;_ and
that way, every user has the runtime actually installed on their computer.