The first macrobutton field in the first cell has a macro reference named 'DoFieldClick'. Change this to 'Unhide' and copy that field to all the other cells. Then add the following macro to the document's 'ThisDocument' code module:
Code:
Sub Unhide()
With Selection.Cells(1).Range
.Font.Hidden = False
.Fields(1).Code.Text = Replace(.Fields(1).Code.Text, "UnHide", "NoMacro")
End With
End Sub