Please take a look:
Visual Basic Combo Box Tutorial (VB6)
Private Sub cmdLoadFoodCombo_Click()
cboFood.Clear
cboFood.AddItem "Orange"
cboFood.ItemData(cboFood.NewIndex) = 60
cboFood.AddItem "Apple"
cboFood.ItemData(cboFood.NewIndex) = 80
cboFood.AddItem "Banana"
cboFood.ItemData(cboFood.NewIndex) = 105
MsgBox "Food combo box has been loaded.", _
vbInformation, _
"Combo Box Demo"
End Sub