You can import custom ASP.NET tags into Dreamweaver.
Before you begin, make sure that the custom tag is installed on the testing server defined in the Site Definition dialog box (see Specifying where dynamic pages can be processed). Compiled tags (.dll files) must be placed in the site roots /bin folder. Non-compiled tags (.ascx files) can reside in any virtual directory or subdirectory on the server. For more information, see the Microsoft ASP.NET documentation.
The Import Selected ASP.NET Custom Tags dialog box appears, listing every ASP.NET custom tag installed on the application server. Control-click (Windows) or Command-click (Macintosh) tags from the list and click OK.