I try to make cell A1, A2, A3 = aa
using code below but getting error “Object required”.

Public Function cellv(ByVal row As Variant, col As Integer) As Variant
     cellv = ThisWorkbook.Sheets("Tree").Cells(row, col).Value
End Function
'---------------------- '
Public Sub testz()
Dim j
For j = 1 To 3
    cellv(j, 1) = "aa"
Next j
End Sub

If I use Debug.Print cellv(j,1) , it work without error.