&使わないほうが速い

Sub Renketsu2()
  Dim str() As String
  Dim i As Long
  
  For i = 1 To 5
    ReDim Preserve str(i - 1)
    str(i - 1) = Me.Cells(i, 1).Text
  Next
  
  MsgBox Join(str, "▲")
End Sub