SCOM 2012 Monitor Physical Memory on Windows 7

Hi,

I've read a few posts on here regarding the monitoring of Physical RAM for windows 7 / server 2008 etc. but they seem to contradict each other.

I would like to monitor how much physical RAM is in use on a machine and if less than 10% RAM is available then throw a critical alert, otherwise healthy. I'd basically like to monitor what you see in task Manager under thePerformance tab > Physical Memory Usage. (No counter exists for this in perfmon).

So far i have played around with the below monitors but they seem to return incorrect results as they monitor a mix of physical and virtual memory.

"Available Megabytes of Memory"

"Percentage of Committed Memory in use"

I just need to be alerted when the physical RAM has almost reached its limit, any ideas on how to do this? 

Thanks