How to get historical Average cost for a certain date

Is there any way to tell what average cost for a part was going back to a
certain date?

Example, What was the average cost of part A101 on 9/1/2010?

There are these fields in parttran table that describe begin qty / after qty as
well as beg* and after* fields for the 5 components of a cost.

However, they don't seem to tell much, they're always empty for any MFG-STK
transactions, and the begin fields just reiterate the cost of the job.