Is there a better way to call macro on cell value change?

Hi,

I currently have a macro that checks one cell ("ChangeTrigger") for a change in formula value on a non-active sheet and if there is a change it then fires another macro ("Macro99"). Problem is that while this macro works, it only seems to work for a change in ONE celI and I need it...or better code...to be able to check for a value change in 3 cells and run one of three different macros depending on which cell had a change in value.

My current code is on the worksheet object:

Private Sub Worksheet_Calculate()

If range("ChangeTrigger").Value <> ChangeTrigger_Old Then

    'Prevent looping of code due to worksheet changes
    Application.EnableEvents = False
        
    Macro99
        
End If
    ChangeTrigger_Old = range("ChangeTrigger").Value
    Application.EnableEvents = True
    
End Sub

And this little pice of code is atop a module:

Public Databases_ChangeTrigger_Old As Double

Thanks,

Lawrence