Never mind, I figured it out. Here is an example for those who are interested:
<target xsi:type="Database" name="accessDb" dbProvider="oledb">
<commandText>insert into LogTable(message,time_stamp) values(@message,@time_stamp);</commandText>
<connectionString>Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\temp\access.mdb;User Id=admin;Password=;</connectionString>
<parameter name="@message" layout="${message}" />
<parameter name="@time_stamp" layout="${date}" />
</target>
<logger name="*" minlevel="Debug" writeTo="accessDb" />