Help creating plugin for a custom panel window

I need help creating a plugin that creates a new window panel for use within Adobe Illustrator. Similar to the "Info" display on the Navigator window panel, I am looking to actively display a Surface Area Value (of  the actively selected object) with 4 User-Defined fields. All this data feeds into one final displayed field at the base of the panel. 

I have built this functionality in Illustrator in a .jsx script but now I would like to have it so the information is displayed actively in a custom panel window. The user can jump around selecting objects and the panel would display the Surface Area info just like the X and Y coordinates are displyed on the Navigator. 

Any insight would be much apprciated. 

Thank you!