Well it's a combobox1_change event right?
So, if the combobox1 is in your userform, it probably is a userform module.
To find other events you could use, you will see 2 drop down boxes near the top that are side by side and long.
If you click the left drop down box, it will show you all the lists of objects in the module.
and If you click the right drop down box, it will show you all the corresponding events for the selected object in the left drop down box.
So, you want to go to your userform moduel
click the left drop down box
click combobox1
click the right drop down box
click change
then you will see some kind of this code displayed in your editor automatically
Code:
Private Sub combobox1_change()
End Sub
That's where you will need to write your code in.
If you aren't sure what I mean by change event, let me know.