Makro sehr langsam

Private Sub CommandButton4_Click()
Application.ScreenUpdating = False
For lng = 7 To 37
For b = 5 To 73 Step 6
Sheets("Urlaubsplanung").Cells(lng, b) = ""
Next b
Next lng
For lng = 7 To 37
For lng1 = 7 To 5850
For b = 2 To 73 Step 6
If Sheets("Urlaubsplanung").Cells(lng, 106) > Sheets("Urlaubsplanung").Range("BP37")  _
Then Exit For
If Sheets("Urlaubsplanung").Cells(lng1, 106) = Sheets("Urlaubsplanung").Cells(lng, b)  _
Then
Sheets("Urlaubsplanung").Cells(lng, b + 3) = Sheets("Urlaubsplanung").Cells(lng1,  _
109)
End If
Next b
Next lng1
Next lng
Application.ScreenUpdating = True
End Sub