I'm not sure what you mean by a sub-row. I imagine it is just a matter of adding another recordset filtered by the categoryID row of the first one.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.