How to add screentip on cross-reference inserted as hyperlink?

Hello,
I would like to add a custom screentip on a hyperlink created with cross-reference (selecting insert as hyperlink check box). I know how to do it using "insert hyperlink", however I would like to create the hyperlink on a numbered item that appears automatically when using "insert cross-reference" but does not appear when using "insert hyperlink". I know that I could create a bookmark on this item and use insert hyperlink after but I have a lot to do and I don't want to create bookmark on all the numbered items. When creating the hyperlink via cross-reference, the default tooltip is "Current document, Ctrl+click to follow link". I would like to replace "Current document" with a custom tooltip. Is it possible? If yes, how could I do it?

Thank you very much!