Automate select file dialog - Webbrowser

Hello,
I want to automate a website with the webbrowser control(.net) where I have to upload a file. This is the input element where I want to add the path:

SetAttribute or InnerText don't work. I read that this is because of security reasons. After Invoke("click") the default "select file" dialog open. And that stops the whole tool.
And now I have no idea how to automate this. Of course I can run an other tool which send keys, but that is very bad and awkward. Besides i want to run my tool at the background.

So do you have an idea? I have already searched a lot..
Thanks, I will add rep for the solution.
Greetings!

PS: Yes, because of javascriopt I need to use the webbrowser control and not httprequest.

I didn't look at the article in detail but it might help you:

http://www.codeproject.com/KB/aspnet/set-webbrowser-file-input.aspx

Edit: The link above might not have a working solution for you so I guess that you should take a look at this site instead:

http://stackoverflow.com/questions/1696750/submit-file-in-form-from-c

Many many thanks, bro! The first one is what I was looking for! After hours of working I got a great result.
Thanks!

Hey no problem! I know how it feels like to be stuck in one small thing which just doesn't work!