Modify URL Structure of OScommerce website

I am trouble with my OSCommerce website url. It sometimes is under "Size" catalog but not others which contain better keywords. e.g. Google Search NATO22006GD. It's our unique item SKU. First result will be ours of course. But its url is "[login to view URL] › Catalog › all 22mm strap" Such "all 22mm strap" is not what we need. We want the url to be "[login to view URL] › Catalog › NATO classic › 22mm" which contain word "NATO". Contain such "NATO" may get better SEO we believe. Could you modify it? Or please let me know if you do not understand my description of task.