Uh, well what you want is the normal map right? The purple-ish texture that gives the texture some depth, right? If that's so then get smart-normal: its a seperate plug in for adobe, you can then export the texture that needs the normal made into a png file or jpg, then import it into smart normal and export with the same name (dont edit the export name) import that into photoshop and then export as dds with it's proper file name