It will be a hard thing to code, you will have to use lines and lines and lines of Ajax, JQuery, JavaScript and PHP. Also it will not work as good as you hoped.
Also once you release the code the person using the code will probally be begginers in this kind of codding so they will need to edit it all to there own server and allow IIS permissions to write and edit a directory.
Personally i think this is a bad project and it's not worth the time codding.
If you want to edit your CMS without logging into it just create a simple php shell that is guarded by a session manager and this will allow you to edit the code.
On topic: If you actually do this congratz, it will be a hard project and i don't see the point personally.
Also once you release the code the person using the code will probally be begginers in this kind of codding so they will need to edit it all to there own server and allow IIS permissions to write and edit a directory.
Personally i think this is a bad project and it's not worth the time codding.
If you want to edit your CMS without logging into it just create a simple php shell that is guarded by a session manager and this will allow you to edit the code.
On topic: If you actually do this congratz, it will be a hard project and i don't see the point personally.