Until a few weeks, I could submit this following form (https://contact.mercedes-benz.fr/catalo ... s/classe_a) dynamically using my VP 7.3 mshtml application, I and all was ok.
But now, it's no more possible => I suppose the site has changing because I don't see the fields in the source-code of the HTML page.
The page is created dynamically by scripting code. I.e. the initial HTML mainly contains (links to) scripting code. When this code run it will update the Document Object Model (DOM) in the browser.
If you can get MSHTML to not only load the HTML, but also execute the scripts, then it should be possible for you to inspect the resulting DOM.
I will warn you that it seems that Microsoft is fading out MSHTML and the Web Browser control in favor of Internet Edge components, and it also seem that the Edge components will only be available to .net programmers.