As
SA suggested you, the task scheduler can be used to set programs to run at a specific time. as you are looking for a code for this but the advantage of scheduling something with the AT command is that your program does not need to remain running on the system all of the time.
The task scheduler will start your program at the right time, it can execute and then it exits. You might need to tweak your program a little to have it backup automatically and then exit but that should be possible.
Actually
How To Use the AT Command to Schedule Tasks[
^]. AT command is much better for accomplished this task.