Public Function setFormCtlDefValue(ByVal theForm As Form, _
                                   ByVal TempTables As String, _
                                   ByVal TempFieldsCtl As String, _
                                   ByVal orderCtl As String, _
                                   Optional TempWhereSql As String = "") As Boolean

'=========================================================================================
'-函数名称： setFormCtlDefValue
'-功能描述： 根据记录设置子窗体默认值
'-输入参数： 参数1：theForm 　　　窗体名称
' 参数2：TempTables　　表名称
' 参数3：orderCtl　　　排序字段
' 参数4：TempWhereSql　临时的where语句
'-返回参数： True 为设置成功，False 为设置失败
'-使用示例： setFormCtlDefValue Me, "表名称","字段1,字段2,字段3", "排序字段"
'-相关调用：
'-使用注意：必须引用ADO
'-兼 容 性：
'-参考资料：
'-作 者： cuxun
'-创建日期： 2008年6月9日
'========================================================================================
    Dim Conn As ADODB.Connection
    Dim abString() As String
    '''用逗号分隔
    Dim rst As New ADODB.Recordset
    Dim strSQL As String
    Dim i As Integer
    setFormCtlDefValue = False
    '如果窗体是新记录状态就退出函数
    If Not theForm.NewRecord Then Exit Function
    Set Conn = CurrentProject.Connection
    If Right(TempFieldsCtl, 1) = "," Then TempFieldsCtl = Mid(TempFieldsCtl, 1, Len(TempFieldsCtl) - 1)
    abString() = Split(TempFieldsCtl, ",")
    If Len(TempWhereSql) > 0 Then TempWhereSql = " where " & TempWhereSql
    strSQL = "Select top 1 " & TempFieldsCtl & " FROM " & TempTables & TempWhereSql & " orDER BY " & orderCtl & " desc;"
    rst.Open strSQL, Conn, adOpenKeyset, adLockOptimistic
    If Not rst.EOF Then
        For i = 0 To UBound(abString)
            theForm.Controls(abString(i)).DefaultValue = "'" & rst(i) & "'"
        Next
    Else: setFormCtlDefValue = False
        Exit Function
    End If
    setFormCtlDefValue = True
    rst.Close
    Set rst = Nothing
    Set Conn = Nothing
End Function

示例下载：http://www.accessoft.com/article-show.asp?id=2186