VBA To Create Word File And Add A Custom Property To It

I have an Excel sheet with a long list of data. A short example is shown below:

Section | Title | Item
1 | INTRODUCTION | a
1.1 | title2 | b
1.2 | title3 | c
1.2.1 | title4 | d
1.2.2 | title5 | e

I made a VBA macro in Excel that runs through this list and creates a new Word file for each item. The filename of the document is based on the data in the Excel file (section and title). Now I would like to add a custom property to each of the newly created Word files, i.e. the value in the 'item' column. Does anyone of you know how I should do this? Or should it be better if I write a macro in Word that runs through the Excel data to create the word files? Here is the code I use to generate the word files: