I've gotten some advice about how use the code below to populate ComboBox1
with letters instead of the numbers as below using the Chr() function, but I
can't make heads or tails of where to put it. I'd appreciate any help.

Private Sub UserForm_Initialize()
Dim iCtr As Long
For iCtr = 1 To 10
Me.ComboBox1.AddItem iCtr
Next iCtr
End Sub