Setting a file to upload inside the WebBrowser component

[vbseyyed]

I have a simple web page that allow file to be uploaded, the upload page
looks like the following:

<form method="post" name="upload" enctype="multipart/form-data"
action="processupload.aspx">
<input type=checkbox name="chkOverride" value="1">
<input type=file name="filename">
<input type=submit value="Upload Data File" name="cmdSubmit">
</form>

My question is without using the web page, how could I use something in
System.Net such as HttpWebRequest or WebClient or some kind to
programmatically upload a file along with sending the checkbox to that
upload page?
I found many solutions in C# but I want it in VB.Net

Thanks,