ADOX(Microsoft ADO Ext. 2.X for DDL and Security)の参照設定が必要。
Dim startNo As Long
startNo = InputBox("開始Noを指定してください。")
Dim cat As New ADOX.Catalog
Set cat.ActiveConnection = CurrentProject.Connection
With cat.Tables("テーブル名").Columns
.Item("フィールド名").Properties("Seed") = startNo
.Refresh
End With
Set cat = Nothing