Hi Talat,

Try this:

Option Explicit
Sub Macro1()

    Dim lngEndRow As Long, _
        lngMyRow As Long
    
    lngEndRow = Sheets("recipient").Cells(Rows.Count, "B").End(xlUp).Row
    
    Application.ScreenUpdating = False
    
    For lngMyRow = 1 To lngEndRow
        'If the uppcase value of the entry in row 'lngMyRow' in Col. B of the 'recipient' tab is P1234EN, then...
        If StrConv(Sheets("recipient").Range("B" & lngMyRow), vbUpperCase) = "P1234EN" Then
            '...copy the value in Col. C of that row to the same row number in Col. B of the 'donor' tab.
            Sheets("recipient").Range("C" & lngMyRow).Copy Destination:=Sheets("donor").Range("B" & lngMyRow)
        End If
    
    Next lngMyRow
    
    Application.ScreenUpdating = True

End Sub
Regards,

Robert