Hi kosenrufu,
the best way is to ask your Excel! :)
Start macro recording, select your graph and perform needed actions. Then stop recording and see result.
You'll get something like
ActiveChart.SeriesCollection(1).Name = "='Sheet1'!$B$1"
ActiveChart.SeriesCollection(1).Values = "='Sheet1'!$B$2:$B$3"
ActiveChart.SeriesCollection(1).XValues = "='Sheet1'!$A$1:$A$3"
You may assign a range directly without manipulating strings, i.e.
ActiveChart.SeriesCollection(1).Values = MyRange
Alex