Read regex value from array to set PopUpButton accordingly

Question

I've got an XML file which I read in as a mutable array (NSMutableArray). It stores information like

( as given out by *NSLog(@"%@:%s GUI data: %@", [self class], cmd, guiData); )

{
    Name = "PopUp1";
    RegEx = "^(Person|Group|Other)\Z";
    Description = "Please select from list...";
    Title = "Type";
}

So now, how do I access the array to retrieve the item named PopUp1 and then find out the RegEx - and then convert it to something so that I can set the selectable content of a PopUpButton?

I use the regexkit framework btw.