How do you record a SharePoint SPListItem SetValue?

Hi,
I'm trying to set a value on an SPListItem inside the Recoder but I dont know how to set the recorder to expect a list item using something like:
item["CustomerName"] = "Bob Jones";

Is there an example somewhere of this?

//////////////////////////////////////////////

using (RecordExpectations recorder = RecorderManager.StartRecording())
{
// dont know how to tell recorder to expect a set.
// the only thing I can find is AssignField() but dont know how to map
// this.
}

//////////////////////////////////////////////


Thanks :)