Many years ago, I got this add-in from John Walkenbach's website. Helpful for adding custom labels to your chart(s). Since then, I've been unable to find the link to original source. The tool was provided freely with description that it may be freely distributed. I take no credit for the attachment, I'm merely storing it here so that others may benefit from it.
Note that this is an add-in that needs to be loaded into your XL application, not a regular workbook.
Note that this is an add-in that needs to be loaded into your XL application, not a regular workbook.