REVERSE LOOKUP ON A PROPERTY OWNED IN AN LLC

Hey guys!

So im looking at a property now i would like to speak with the owner on or find a number too and the house in owned in a LLC name.....I

f i am trying to contact him/her and the mail address is to a po box, what should i do? Is there an inexpensive way to do a reverse lookup or any better advice you would suggest?

Thanks in advance