Thanks Andy.

I came up with this grubby but effective (so far) code:

Dim sFormulae As String
sFormulae = chtEvent.SeriesCollection(1).FormulaR1C1
' worksheets can appear in the formulae in two forms:
' "=SERIES(Data!R1C2,Data!R2C1:R10C1,Data!R2C2:R10C2 )
' "=SERIES('My Data'!R1C2,Data!R2C1:R10C1,Data!R2C2:R10C2)

If InStr(sFormulae, "=SERIES('") 0 Then
' sheet name is enclosed in single quotes:
Debug.Print "[" & Mid$(sFormulae, Len("=SERIES('") + 1, InStr
(sFormulae, "'!") - Len("=SERIES('") - 1) & "]"
Else
' sheet name is NOT enclosed in single quotes:
Debug.Print "[" & Mid$(sFormulae, Len("=SERIES(") + 1, InStr
(sFormulae, "!") - Len("=SERIES(") - 1) & "]"
End If


Chrisso