How to use stored proc inside log4net configuration for SQL Server for logging

How do I update the commandText and parameter section for stored procedure so that I could log the errors into SQL Server via log4net?

I am using SQL Server 2008, and my appender configuration looks like this:

<appender name="ADONetAppender" type="log4net.Appender.ADONetAppender">
  <bufferSize value="100"/> 
  <connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/> 
  <connectionString value="server=MYSERVER; uid=MYUSER; pwd=MYPASS; database=MYDB"/> 
  <commandText 
    value="INSERT INTO Log ([Date],[Thread],[Level],[Logger],[Message],[Exception]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception)"

    />
  <parameter>
    <parameterName value="@log_date"/> 
    <dbType value="DateTime"/> 
    <layout type="log4net.Layout.RawTimeStampLayout"/>
  </parameter>
  <parameter>
    <parameterName value="@thread"/> 
    <dbType value="String"/> <size value="255"/> 
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%thread"/>
    </layout>
  </parameter>
  <parameter>
    <parameterName value="@log_level"/> 
    <dbType value="String"/> 
    <size value="50"/> 
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%level"/>
    </layout>
  </parameter>
  <parameter>
    <parameterName value="@logger"/> 
    <dbType value="String"/> 
    <size value="255"/> 
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%logger"/>
    </layout>
  </parameter>
  <parameter>
    <parameterName value="@message"/> 
    <dbType value="String"/> 
    <size value="4000"/> 
    <layout type="log4net.Layout.PatternLayout">
      <