the categfory that is displayed is taken ffrom the querystring.
for example:
products_results.php?Search=1&ProductCategoryID[]=3
loads category id 3
you will need to know the id for the category and set the querystring to include it.
In my test store, id 3 is CDs, so i could duplicate the product result page as:
cds.php and call it as:
cds.php?Search=1&ProductCategoryID[]=3
to load the proper category.