web link to an exe or dll

Hi!
For some strange reason, I have to accomplish the following from a web page:

<img src="app.dll?id=12345">
or
<img src="app.exe?id=12345">

the exe or dll application has to search in a database for the id 12345 and return the image associated to that record.

The questions are:

-how do I make a dll or an exe return data with a content type image/gif or whatever?
-how can I read parameters passed by the querystring from inside the app?
-Can it be done with Vb6 or should I make a static library using C?
-Am I gone mad?

thanks everybody!!! :)

The easiest way would be to use an ASP page (essentially the same as a VB program), but that assumes your web server supports ASP (or IIS).

There are many examples on the web of doing exactly what you want (I'g guess that there are several on this forum).

thanks for the answer,
the problem is this website will be released on cd-rom so I'd like to run it without a webserver and still get dynamic content.

I know some products exist that can run a webserver from cd (such as Dynamic-CD and ALP) but I'm no so confident with their performances.

And there's more: my website will involve cryptography so I'm not so happy that anyone could see what's going on just opening the asp page. I would rely on compiled code or something... I cannot install the .net framework either, that would make things much easier :(