OK. I looked this up and got the answer I was looking for (see code below)

Private Sub Worksheet_FollowHyperlink(ByVal Target As Hyperlink)
TmpRef = Chr(ActiveCell.Column + 64) & ActiveCell.Row
If Not Intersect(Target.Parent, Range(TmpRef)) Is Nothing Then
Call Unhide_Sheet
End If
End Sub


This all works fine and I have now started using the functionality when
building spreadsheets. My problem comes when users of Excel 97 (I use 2000)
take the same spreadsheets and try to run the hyperlinks. The macro does not
work.

I this because the code is not supported in Excel 97?

Please help!