Use Facebook API to determine webpage share on a specific domian using VB.NET

We want to find out if a Facebook user shareed our webpage. We need a software developed in VB.NET or a library that can be used in VB.NET that only ask the input of the Facebook userlink(s) in the form of [login to view URL] Using only this information the software needs to determine if our webpage has been shared by the userprofile(s) inputted. We prefer that the user would not be logged in for the software to perform this task, but if a user does have to be logged in, the software has to be able to determine that other user profiles have shared our webpage so that the software can determine multiple userprofile with one click. We suggest that this project contain only 3 controls on a winform: a multiline textbox, a status label, and a command button to excecute the process. The user should be able to enter multiple facebook profiles at once in the textbox.