List Boxes Fed From Queries

Hi peeps

I have a list box that contains 4 fields and the list box is located on a form.
One of the fields on the form is [Date logged]. This is also colum 2 of the list box.
I am trying to write some code to say that if the Date logged on the form is different to the one in the list box, run an append query.
Basically, the principal behind this is to have an audit trail of when records have been ammended. The first time a record is created, a base record is created. It is this base record that will populate the list box along with all other record changes that occurr from that point on.
I am trying to say that if the [Date logged] does not match the last record in the list then it knows it needs to append the record to the history table again as a change has been made. I would really appreciate some help here folks. Thanks so much! :-)