As with everything in this forum there are always multiple options available. Here is mine:
1.) Create a module for your application.
2.) Create a public function that passes a combo box
from your form as a parameter and returns a combo box
as a value.
Public Function fncFillComboBox(ByVal cbo As ComboBox) As ComboBox
'* Simply filling the combobox with numbers.
For intX As Integer = 0 To 5
cbo.SelectedIndex = 0
'* Return the combobox to your calling form.
fncFillComboBox = cbo
Assuming a simple example form with a button and a combo box
here is sample code to fill your combo box:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Me.ComboBox1 = Module1.fncFillComboBox(Me.ComboBox1)
You could easily change the example function to pass not only the combo box but also an SQL statement that could be processed within the function.