i appreciate your help. i had considered these options before but could'nt work it out.
like you said, the string sys function worked just fine. it was heartning to see calc.exe run, but things were short lived. when i tried to give other commands, it failed to execute and GUI stopped responding, even though its process was running (as seen in task manager).
when calc.exe did run, the GUI app was left unresponsive till calc.exe was closed.
is there anything else i need to do or consider?
also the cmd window remains hidden. can i show the cmd window?