Macro, Récupérer plage données variable en taille et position selon un critère

'------------------------------------
Sub test()
Dim PremLig As Long, DerLig As Long, Rg As Range
With Feuil1 ' Worksheets("Feuil1") 'nom feuille à adapter
    'Comme ta plage est toujours en B:D colonnes
    With .Range("B:D")
        PremLig = .Find(What:="KOORD", After:=Range("B1"), _
                LookIn:=xlValues, LookAT:=xlPart, _
                SearchOrder:=xlByRows, SearchDirection:=xlNext).Row
         DerLig = .Find(What:="KOORD", After:=Range("D" & PremLig), _
                LookIn:=xlValues, LookAT:=xlPart, _
                SearchOrder:=xlByRows, SearchDirection:=xlNext).Row
    End With
    Set Rg = .Range("B" & PremLig, "D" & DerLig)
End With
MsgBox Rg.Address
End Sub
---------------------------------------