Change cell value that has data validation from list in a separate sheet with macro?

Hi!

I am wanting to write a macro that can change the value for a data validation cell. This is an order form that I want to have default parts to order based on a selection of a system. For instance, if the user selects "small system" the form is loaded with the default parts for a small system. Sheet1 is the order form and sheet2 is the parts table. The part description cells are a validated list from the sheet two table. Is it possible to write a macro to change these values? I have this VBA code to run the macro when a system is selected:

Private Sub Worksheet_Change(ByVal Target As Range)
If Intersect(Target, Range("C3")) Is Nothing Then
Exit Sub
End If

If Range("C3") = "Small" Then
SmallSystemMacro
End If

End Sub

Just need to know how to write the macro: (The name of the named list is "PartList")

Sub SmallSystemMacro()

.
.
.
..

End Sub



Thanks!