2 Numbers, 1 Spin Button

Okay so the background is a bit of the following, I'm trying to edit 1 number by an incriment value of 1, while another number is also edited using a backwards calculation dependant upon the value of the first number being edited. The problem here is two-fold: first the number in the second column doesn't change unless I click 'run', and secondly, the number it keeps returning is wrong (I think it's just doing it the once).

The code I'm using is the following:

Sub Spinner13_Change()

End Sub

Private Sub SpinButton13_SpinDown()
    Dim incrimentVal As Integer
    
    With Range("D3")
        Select Case Range("D3").Value
            Case Is < 10
                incrimentVal = -1
            Case Is < 12
                incrimentVal = -2
            Case Is < 15
                incrimentVal = -3
            Case Is < 17
                incrimentVal = -4
            Case Is < 100
        End Select
        Range("M4") = Range("M4") + incrimentVal
    End With
End Sub
Private Sub SpinButton13_SpinUp()
    Dim incrimentVal As Integer
    
    With Range("D3")
        Select Case Range("D3").Value
            Case Is <= 10
                incrimentVal = -1
            Case Is <= 12
                incrimentVal = -2
            Case Is <= 15
                incrimentVal = -3
            Case Is <= 17
                incrimentVal = -4
            Case Is <= 100
        End Select
        Range("M4") = Range("M4") + incrimentVal
    End With
End Sub

The first number, and the number the spinner is currently tied to is "D3", the second number that is supposed to change based on that value is M4. I also want to eventually tie a restriction that M4 cannot be less than zero for changes to occur in D3, but that might take a bit longer.

The second code I have is trying to edit the minimum value of the spinbutton when the user clicks a checkbox (hence declaring they are done with this portion of the edit). The code I'm using is:

Sub CheckBox12_Click()
         Spinbutton13.Min = Range("D3")
End Sub

But it keeps returning 424 error. Any help with either of these things would be appreciated. Thanks. By the way.. if there is a list of functions that can be run in excel using VB that would be extremely helpful ^^