By executes do you mean the program executes?
Honestly to me at this point it looks like the executable is not being called since there is a space in the path, cmd.exe won't know what to do.
"/C C:\\Program Files (x86)\\.....>MyApp.exe -input \""+ Locals.Source_File+"\" -format s19 -output\""+ Locals.Destination_File+"\""
I would suggest turning that into this
"/C \""C:\\Program Files (x86)\\.....>MyApp.exe"\" -input \""+ Locals.Source_File+"\" -format s19 -output\""+ Locals.Destination_File+"\""
You can see if I put the first one into cmd.exe the exeutable never launches because of the path (the space right after Program. But if I put the path to the executable in quotes as well it actually launches. (The red lines are just my name so I got rid of them)
Another thing you can try to do is see what cmd.exe is actually outputting. If you click on the Standard Output/Error, put the Output and Error into a local variable so you can see what is being returned.