ObjectQuery by reflection

Hello guys!

   I'm trying to do something like this with reflection and no luck...

this.EFMODELINSTANCE.Entry((PERSON)instance).Collection(d => d.somePersonProperty).Query().Count();

what i'm trying to achieve is getting the count of the navigation property items in an property like

Person -> Address

I want to count all the addresses for an instance of a Person.

So, i want to make a generic method that receives Object (an instance of EF) and a string with the name of the property to count.

Can you help me on this? :)

Thanks in advance!