Context sensitive "message" or comment required

In Excel, a comment linked to a cell "pops up" when you cursor on the cell.

I want a similar capability in document templates using Word 2003.

For example, the template may have a section to add specific content
("Describe the market") and the pop up message would provide specific
instructions or explanations ("focus on xyz and provide abc data").

The example is knaff, but I am looking for an alternative to laying out
individual sub-sections in the template.

Any clues? (apart from the use of comments or autotext)

Thanks.