@thomthom said:

Maybe you can make a Ruby C Extension work for you?

Ruby C extension? seems useful! thanks.

Thank you so much!! The ABC.exe is written by me and I will take a look at Win32ole first.
By the way, I have been thinking about using DLL to receive message and then call a ruby function to collect the data. But it seems not easy to run ruby on Visual studio so I finally give up.

This is what I've done so far: wrote a plugin using "Win32API" to send message to other program (e.g. tell ABC.exe to calculate sth..). But now I want to let SU knows the calculation is finished in ABC.exe (e.g. may be sending WM_COPYDATA message back to SU). Is there any callback function in SU can be used to check it?

Thanks