Select the 30 cells, then run this macro:
'--------------------------------------------
Sub InsertComment()
Dim rCell As Range
Dim sText As String
For Each rCell In Selection
sText = sText & rCell.Text & vbLf
Next rCell
On Error Resume Next
Set rCell = Range(InputBox("Cell to comment"))
On Error GoTo 0
If rCell Is Nothing Then
MsgBox "Invalid input"
Exit Sub
End If
rCell.ClearComments
rCell.AddComment sText
End Sub
'-------------------------------------------------
HTH