What is it that you are trying to do? Are you trying to bet on a gold price collapse by shorting the company that has the highest production costs per ounce of gold? Some odd years ago, I tried to put together a portfolio product that traded futures against stocks based on my Ph.D./CFA level analysis of stock sensitivity to commodity price movement (which is to say that my analysis was vastly more sophisticated than AIPC or something). There was tons of demand among clients for this kind of product and if I could have gotten something good, I could have gotten $100M invested in it in no time (which would mean I would expect about $2M annually in income for me to spend on toys and liquor). I couldn't get it done. In the end, the profitability of these companies is only lightly related to the relationship between commodity prices and production costs as the people who run them aren't idiots and the stock price is even less related.
If you put together a convincing demonstration of a portfolio trading natural resource stocks against natural resource prices, I would pay you $1M for ownership of that work (or you could just settle this irksome Riemann hypothesis thing and get your Millenium prize of $1M which show you how messed the world is). But I don't think it is possible.
