I am working on automating a regression analysis for our field staff but I am running into a problem referencing the cell range for the regression. Essentially, I have a pre-made form that the sales staff fills out and then runs one of two macros depending upon what type of regression analysis is desired. These macros populate the data form that is the base of the regression analysis. This form could have anywhere from 1 to 88 entries. I am trying to find the last cell used (yLast) in the named range and by using an offset set the xLast cell. I can find the last y value cell and get the offset to the xLast cell but when I try to use these as a reference in the regression code, I get an "application or object defined error.

Here is the code:


 
Private Sub CommandButton1_Click()

'code to run regression analysis
Dim yFirst As Range
Dim xFirst As Range
Dim yEnd As Range
Dim xEnd As Range
Dim yRng As Range
Dim xRng As Range
With Range("RegRng")
    Set yEnd = .Cells(.Cells.Count).End(xlUp)
End With
Set xEnd = yEnd.Offset(0, -1)

Set yFirst = Sheets("Data Summary").Cells(10, 5)
Set xFirst = Sheets("Data Summary").Cells(10, 4)
     
 'code to run regression - This is where the error occurs
     Application.Run "ATPVBAEN.XLA!Regress", ActiveSheet.Range("$e$10:$E$" & yLast), _
     ActiveSheet.Range("$d$10:$d$" & xEnd), False, False, , "Analysis", False, False _
        , False, True, , False
    ActiveSheet.ChartObjects("Chart 1").Activate
    ActiveChart.ChartArea.Select
    ActiveChart.Location Where:=xlLocationAsNewSheet, Name:="Chart1"
    Sheets("Data Summary").Select
    ActiveWindow.ScrollRow = 1
    Range("G10").Select
    ActiveCell.FormulaR1C1 = "=SUM(Analysis!R17C2+RC[-3]*Analysis!R18C2)"
    Range("G10").Select
    Selection.AutoFill Destination:=Range("G10:G99"), Type:=xlFillDefault
    Range("G10:G99").Select
End Sub
Any help would be greatly appreciated.

Tim