I know this is an old post, but I experienced the same thing as the OP, and for anyone trying to figure it out, the caret key can help you pass the correct characters to the system exec command.
For example... I had the command:
cmd /k "..\Get Data\My Data.exe"
To get it to work, I had to change my string to:
cmd /k ^"..\Get^ Data\My^ Data.exe^"