2 processes using CreateProcess() function, one starting another

Since I haven't found any solution to my problem, I would like to ask for help myself.

I've got a task like this:

• A program consists of 2 processes, first process shuffles N numbers in a range of 1...100 and writes them to file. N is passed as a parameter while starting the program
• Process 1, before shuffling numbers, starts the 2 process, which waits for a file to be available (spinlock)
• Process 2, once it has access to file, read the numbers from the file, calculates the avarage and prints it on the screen, Process 2 ends
• Process 1 ends after process 2 (WaitForSingleObject)

The whole thing needs to be done on one main.exe file. How do I create 2 processes, both starting the same file? Is there any efficient way of approaching this task?

NOTE: I don't need any help on shuffling the numbers, creating file or reading from it, I wanted to present the whole task so that you could think of it as a whole. I only want to know the way those 2 processes should be started.