exec child prog from parent

I have a mian menu program of which three of the options are to
execute child programs and basically I can't seem to get it going.

All four programs are completed but I can't seem to link them
together.  All the text books I have are useless in this area.

I've managed to figure out that it's got something to do with the
- exec - command in the DOS unit and other related commands are    
- swapvectors - and - DosExitCode -.

But I seem to be going around in circles.

main prog

parent - login2.pas

child progs - password.exe

If anyone know the correct syntax to do this could they possibly
send it to me please.

Thanks in advance.