Private Sub Comment_DblClick(Cancel As Integer)
Dim str As String
Me.Refresh
str =  "Комментарий "  & Me.ИмяПоляВкоторомСтоишь &  ".ИмяФормы" 
DoCmd.OpenForm  "Extension" , acNormal, , , , acDialog, str
End Sub

Option Compare Database
Dim frmName As String, controlName As String, chilli As String

Private Sub Form_Close()
If IsNull(chilli) Or chilli =  "" Then
Forms(frmName).Controls(controlName) = Me.Comment
Else
Forms(frmName).Controls(chilli).Form.Controls(controlName) = Me.Comment
End If
Forms(frmName).SetFocus
End Sub

Private Sub Form_Open(Cancel As Integer)
Dim str As String
str = Me.OpenArgs
Me.Caption = Left(str, InStr(str, " . ") - 1 )
str = Right(str, Len(str) - InStr(str, ". "))
controlName = Left(str, InStr(str, " . ") - 1 )
str = Right(str, Len(str) - InStr(str, ". "))
If InStr(str, " . ") = 0  Then
frmName = str
Me.Comment = Forms(frmName).Controls(controlName)
Else
frmName = Left(str, InStr(str, ". ") - 1 )
str = Right(str, Len(str) - InStr(str, "."))
chilli = str
Me.Comment = Forms(frmName).Controls(chilli).Form.Controls(controlName)
End If
End Sub