I don't quite understand, but you can try to do like below.
Private Sub Workbook_Open()
Dim UserName As String, d As Object, i&
Set d = CreateObject("scripting.dictionary")
d.Add "dlagm001", "Ivan"
d.Add "blago001", "Ivan"
d.Add "kolev003", "Nadya"
d.Add "aptul001", "Birhan"
d.Add "karag001", "Nikolay"
d.Add "ramis001", "Semra"
d.Add "gueor001", "Ianko"
UserName = LCase(Environ("UserName"))
If d.exists(UserName) Then
MsgBox "Hello " & d(UserName) & " " & vbNewLine & "10.12.2018 change:" & vbNewLine & "!Paste! function is removed for colums:B,C,H,K,L,O,Q."
Styles("Normal").Interior.Color = RGB(240, 255, 255)
With Sheets("KOBU")
.Unprotect "123"
For i = 7 To .[h65536].End(3).Row
If InStr(.Cells(i, 8), Left(UserName, 5)) Then
.Cells(i, 1).Resize(, 11).Locked = False
End If
Next i
.Protect "123"
End With
Else
Sheets("KOBU").Unprotect "123"
Cells.Locked = True
Sheets("KOBU").Protect "123"
End If
End Sub