How to read and write variables to/from a file.

[Captain Hook]

I have a couple of Macros that run all the time on my computer doing various tasks.
I have a variable that increments by one each time the Macro runs. My problem is if I stop the 
Macro and restart it the variable is reset back to 1.  I would like to make it so each time the Macro ends  it increments
by 1 then writes the value to a file. Then the Macro goes back and it sits there waiting for an event to trigger it.
I would like it so if I stop the Macro and restart it the first thing it does is it reads a file and pulls the current value
of the variable so it keeps a running total rather than reseting back to 1.

I hope this explains what I want.

Thanks much in advance.

Captain Hook