How to create function that returns all the selected fields in column "Email_Address" in a view?

How to create function that returns all the selected fields in column "Email_Address" in a view?

Hi, I'm strugling with this one - I have a form where one column is "Email_Address". 
Now I need the user to be able to select appropriate rows in a view and on press of a button get all the email addresses to copy&paste

I've been experimenting with the following code:

string Get_Email_Address()
{
x = i.Email_Address ;
Info x ;
}
return x ;

This just lists of the email addresses in the log, but obviously returns only the last one.
How do I make it to return all of them?
and how do I narrow it down just to return the selected ones? (filetered results or check by user in the view)

Thank you

-Peter