Content Management System

I need to open any kind of html layout copy past the codes and make editable areas for texts and images, like Dreamweaver template creation structure. And the users will be given administrative area, where they can edit those editable areas only. Edit texts, upload images... Currently I'm using an ASP .NET application for the inventory management sites. What I do is I'm creating my desired webpage, copy and paste the given one row text (which is the connection to the database), uploading it to my server, and it is done, I can do all the changes true the admin area. I need something working like this Please provide me working application if you have any I'm open for any professional suggestions