Auto-updating Changes For Params Inside Function Possible?

I am currently facing an heavy struggle with architecturing my VB.Net app.To simplify, i'm using entries from XAML comboboxs, which all trigger OnChange the same routine which manages which Function(s) to use depending on which combobox triggered.The problem i'm facing is for example i have Function(ByVal A As String, ByVal B As Integer, ByVal C as Double, etc...), and it works if the routine calls explicitly for this function's result. But then if another combobox makes for example the variable B to change, then i have to add another "If sender= Then" check for this combobox and recall expicitly the function above (since B is one of its parameters)..In the end, my routine is loooooong like 24 checks with at least 4x duplicates of same functions..is there a simple way to make a Function autoexecute when one of its parameters change without having to be called explicitly by another routine ? (Like Excel formulas do when one of its references change)