Assigning Settings to a Scrollbar (Form Control)

I am trying to assign certain max, min, incremental settings, and cell link to a scrollbar I have put on a worksheet. As this scrollbar is clicked, it should step through time at certain steps, and the cells on that same work sheet, as well as a chart, will be updated with each click of the scrollbar. I tried the below code but got an error every time I clicked the scrollbar saying "Object variable or With block variable not set":

Sub PhasorControl()
    Dim Bar As ScrollBar
    With Sheets("Sheet3")
        Bar = Sheet3.ScrollBars("Scroll Bar 1")
        Bar.Max = Sheet1.Range("D6").Value
        Bar.Min = Sheet2.Range("A2").Value
    End With
End Sub

I have also tried this, but got absolutely nothing:

Sub PhasorControl()
    Sheet3.Shapes("Scroll Bar 1").ControlFormat.Min = Sheet2.Range("A2").Value
    Sheet3.Shapes("Scroll Bar 1").ControlFormat.Max = Sheet1.Range("D6").Value
End Sub

Any suggestions on getting the scrollbar settings assigned? Ideally, I would like to be able to have it start at a value in cell A2 and each increment would be the value of the next cell down (A3, A4, A5, etc.) until the max is reached (A?? - amount of data in column A varies). Thanks for your help!