I've fought with it all day...perhaps it is not possible.
Other question: how can I get the x-axis as character labels instead of numbers? Are my labels too wide?
Dim pdatagraph As IDataGraphT = New DataGraphTClass
Dim seriesprops As ISeriesProperties = pdatagraph.AddSeries("bar:vertical")
seriesprops.SourceData = pTable
seriesprops.SetField(0, "YrMo")
seriesprops.SetField(1, "Number")
Instead of getting 2012_09 (or even 12_09) for my bar labels, I'm getting numbers....1 for the 1st bar, 2 for the 2nd, etc.