Challenge: Moving a shape down/up on a scroll event

Hi all

I'm new to this, but apart from that, this is what I'm trying to accomplish:

I want to create a legend (or something similar) that moves to stay in the right hand corner of an excel document while you scroll up and down on the worksheet.
This will make my work (as an auditor) much easier and also make my working papers look better.

I've been playing around a bit and this is what I've done thus far:

Sub ShapeDown()
    ActiveSheet.Shapes("Rectangle 3").Select
    On Error Resume Next
    With ActiveWindow.Selection.ShapeRange(1)
        .Top = .Top + .TopLeftCell.Offset(1).Height
    End With
    ActiveSheet.Range("C3").Select
End Sub

Sub ResetShape()
    ActiveSheet.Shapes("Rectangle 3").Select
    ActiveWindow.Selection.ShapeRange(1).Top = 12.75
    ActiveSheet.Range("C3").Select
End Sub

I didn't know if a worksheet change event or a scroll event would be the best for scrolling down and in a perfect world the macro should determine the width of the screen and position the shape in the top right corner of the page. The shape should then move to stay in that position as you read through the excel document. I do not want to freeze panes as I want to utilize the total height of the available screen.

I am also open to suggestions.

Thank you guys in advance.