need help passing keystroke to program

I need to write a program that will do the following:

1. open image file using mspaint.exe
2. Then pass keystroke "cntrl-s" to mspaint.exe
3. Then close mspaint.exe

4. and repeat this process till all image files have been processed.


Here is my code so far

Code:

#include <windows.h>
#include <stdio.h>
int main()
{
STARTUPINFO          si = { sizeof(si) };
PROCESS_INFORMATION  pi;
char                 szExe[] = "mspaint.exe";
char                 buf[4444];

if(CreateProcess(0, szExe, 0, 0, 0, 0, 0, 0, &si, &pi))
{
   // optionally wait for process to finish
   //WaitForSingleObject(pi.hProcess, INFINITE);

   CloseHandle(pi.hProcess);
   CloseHandle(pi.hThread);
}
}

I have no problem opening the images, but have not been able to automatically pass the keystoke "cntrl-s" to mspaint.

I have looked at keyboard dumps and other functions but have not gotton far with this part of program. I have no formal coding education so I am a complete novice here. Any help or suggestions would be greatly appreciated.

Douglas

I would use FindWindow() to get the handle to the Paint window and then would use SendMessage().

You could try to reverse-engineer it. Since when clicking on menu items, the paint window will receive WM_COMMAND messages, you could generate and send them too. You can use Spy++ to spy for what messages the window gets and then you'll be able to control the window without hacks n' tricks. Pretty cool.
Just don't expect it to work on newer versions of Paint. Hopefully it will, but again, it might not.