HSMP Extension

I have some queries regarding the HSMP extension that I am going to apply for in August 2009.
I got my entry clearance in October 2007and that time I was serving a humanitarian organization, so completed my contract in Feb.,2008 and after a three months of rest at home moved in to UK.
As soon as I got here I started to look for jobs in UK but as my experience is majorly in emergencies and development phases (humanitarian), so didn't get anything in commercial field.
In the meanwhile I also gave interviews for the different international non governmental organizations of Britain and Ireland.I might be offered a job from them but outside the UK. I want to make UK my home so my family will be staying here and I will be maintaining my bank account in the UK so to receive my salary and pay the taxes.

My query is if I accept a job from Irish based organization but work outside UK, so would I be given extension of my visa or not. As my family would be staying in London and I will be visiting them on my vacation every 10 weeks, or i have to stay in UK, as i am afraid that i will not be able to secure required points in earnings, or there is any other way.
Please,give me proper advice as I have already searched for this information in almost all the websites.
Thank you in anticipation.