Convert custom marks to endnotes

[Apologist]

I have hundreds of documents with citations that are custom marks rather than actual footnotes or endnotes. The custom marks link to the corresponding citation, but not in the preferred way. Unless I use Word's Reference > Footnote/Endnote option, the book publication software cannot import the references (hundreds of them!).




If anyone can suggest a way to convert these custom marks to footnotes/endnotes, I would greatly appreciate your help!