Hi patel45,

Thanks for your reply. I've also been able to make some progress on my own:
    Dim ISIN As String
    Dim REIHE, SPALTE As Integer
    
    'ISIN auslesen
    ISIN = ActiveCell.Value
    'Historische Spreads im HIST Sheet finden
    Sheets("HIST").Select
    Range("A1").Select
    Cells.Find(What:=ISIN, After:=ActiveCell, LookIn:=xlFormulas, _
        LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
        MatchCase:=False, SearchFormat:=False).Activate
    
    REIHE = ActiveCell.Row
    With ActiveSheet
    SPALTE = .Cells(REIHE, .Columns.Count).End(xlToLeft).Column
    End With
    
    Range(Cells(REIHE, 4), Cells(REIHE, SPALTE)).Name = "GraphSpreadRange"
    Range(Cells(2, 4), Cells(2, SPALTE)).Name = "GraphTimeRange"
This gives me the correct ranges back. I thought names ranges would make it easier to refer to when it comes to draw the graph i mentioned in the second part of my thread, but so far no luck... I think i will open a new thread regarding my problem with the graph. Topic of this thread doesn't look right any more.