does you web server support some form of scripting technology (usually PHP, ASP, Coldfusion, CGI etc...). if your web server supports scripting then you can use one of those scripting langauges to manipulate data from to and from the db.
that's be my first stopping off point
having done that then you can worry about whether your editor can connect to MySQL.. my guess would be it can't..because its not part of editing process to do that, unless you have some whizzy editor which does incremental backups in some form of versioning software. editign a script is usually a text editor, providign you know the magic words to drive the script any editor should handle it, although personally Im quite impressed with Chamisofts HTML kit editor for freeware & Macromedia for when I get a job that warrants it.
so does your web account actaully include PHP, or some other scripting language?
the fact you have access to PHPMyAdmin is I suspect a red herring.. That is provided by your ISP to allow you to talk to their database for maintenance of the database NOT it has nothing to do with using it in a web application.
to use a database in a web page you need to be using a scripting language that runs on the server which handles database interactions. Effectively you call for a page from the server, the server notices the file extension and invokes the appropriate scripting engine based on the that extension. So a file ending .ASP would be handled by Active Server Pages, PHP by a PHP parser and so on, HTML/HTM is handled by the HTM parser (effectivley the server sends the file for HTML, and the output/the reulst of the script(s) to the client browser.
So to use a database within your site you will need to write pages in a scripting language, as your server is IIS then the native support for scripting will probably be ASP, but PHP may be available.
Your current 'database' code points to the location: \\iis691\domains\a\aperkin.co.uk\user\
which doesn't actually do anything.. the reason why you are getting errors is that there is no valid html file in that location that the server can access. I'd guess the server isn't allowed for security reasons to render a page from that directory. but as you haven't explicitly stated what file you want the server to retrieve it may be attempting to load the default file index.htm
The best thing to do is to talk to your ISP and find out what scripting languages they provide, what scripting language(s) are available on your account. It sounds to me as if you are just starting on the database backed web development route, in which case you are probably going to get more value form a site like www.w3schools.com may be more useful, until you start hitting db problems that is