MT4 median of OC moving average

Hey, I'm sure this is simple but I can't find how to do it anywhere :S

I'd like a moving average that uses a median of the open and close price (OC/2) not high and low (HL/2) like the MT4 Moving Average median option does.

Is it possible? Needs custom coding, or is it already available? I've tried googling but I just get page after page of useless :S

Thanks for any help given!
~Alan

nobody? ;

Two ways of doing it:

You're a beautiful snowflake! Thanks a lot. Now I'll be rich!