Ešte som našiel na nete toto, ale neviem neviem to makro použiť:
Sub test()
Dim a, i As Long, ws1 As Worksheet, ws2 As Worksheet
Set ws1 = Sheets("Sheet1")
Set ws2 = Sheets("Sheet2")
With CreateObject("Scripting.Dictionary")
.CompareMode = vbTextCompare
a = ws2.Range("a1").CurrentRegion.Resize(,2).Value
For i = 1 To UBound(a,1)
If Not .exists(a(i,1)) Then .add a(i,1), a(i,2)
Next
a = ws1.Range("a1").CurrentRegion.Resize(,3).Value
If .exists(a(i,1)) Then
a(i,3) = .item(a(i,1))
Else
a(i,3) = ""
End If
End With
ws1.Range("a1").CurrentRegion.Resize(,3).Value = a
Set ws1 = Nothing : Set ws2 = Nothing
End Sub