DisplayUnitLabel Property
Returns the DisplayUnitLabel object for the specified axis. Returns Null if the HasDisplayUnitLabel property is set to False. Read-only.
Example
This example sets the label caption to "Millions" for the value axis in Chart1, and then it turns off automatic font scaling.
With Charts("Chart1").Axes(xlValue).DisplayUnitLabel
.Caption = "Millions"
.AutoScaleFont = False
End With