Find and Replace - Value selected at random from a list

Backup your data.
Run: RandomFindAndReplace

Sub RandomFindAndReplace()
    Dim nLastRow As Long, nRow As Long, nRandomRow As Long, str As String
    
    Randomize 'Initialize the random number generator
    
    'Find the last row in column "D"
    nLastRow = Cells(Rows.Count, "D").End(xlUp).Row
    
    ' Start on row 13 to end
    For nRow = 13 To nLastRow
        'Random Row from 3 to 12
        nRandomRow = CLng(10 * Rnd) + 3
        str = Cells(nRandomRow, "E")
        'Replace "[City]" with name in column "D"
        str = Replace(str, "[City]", Cells(nRow, "D"))
        'Place result in column "F"
        Cells(nRow, "F") = str
    Next nRow
End Sub