You get the distance either by using the formula for distance (a²+b²=c²):
d = sqrt((x2-x1)^2+(y2-y1)^2)
Or you use an extension that provides that formula for you.. (the distance function really should come with MMF2 by default.. REALLY - you use it like 100 times as likely as stuff that does come with MMF.. like ln or arcsin).
My weapon of choice is usually the Advanced Direction Object, as it contains lots of neat functions like that, so I have it in most games anyway. But there are also others that can do it, like the Advanced Math Object.
About the "oh cmon dude" that's just.. I believe it's really really simple to make the example work for multiple objects.. so I think I just repeatedly fail to estimate your skill level, no offense
PS: You should write a little something about your team on your website. If I was a client considering using your services, that's the first thing I would look at. Preferably with a professional but congenial looking foto, like so.