Flex particles position - Update parameters

I wat to ask you about a problem that I have with the extraction data from Flex in UE4.
I have a Flex Actor and I need to extract position of a object inside it (marge 2 flex actor). There is a method for extract flex particles position in real-time?

Another question: It is possible update flex parameters in real-time? (Like number of particles, cluster radius, particle spacing ecc…)