Some time ago, Greg Maxey and I developed an add-in providing simple access to document variables, bookmarks, and document properties, but we had different sets of priorities with where we wanted to take the add-ins, so while he developed his with the emphasis on Content Controls, I removed the Content Controls components and made a more simple tool.
My version is at
http://www.gmayor.com/BookmarkandVariableEditor.htm, his you can find linked from that page.
Which brings us back to your question. The add-in will show at a glance what is inserted in the document, and will provide the means of editing values.
I quite like to use Document Variables to store data, and these can be displayed using DocVariable fields. Any field including cross references you use to display data can be unlinked and it then becomes text which you can modify.
You can use this tool to help determine how you want to store the document information you require and then, you can create a VBA userform to store exactly what you want, where you want it, and to generate the numbers that you want to store.
If you decide you prefer content controls, then Greg's web site will tell you far more than you thought you needed about using these controls.