submitting to a server

OK, this must be a very very simple question for ASP programmers to answer.
After I have gathered all the information I want from the user and after
the user has clicked on a submit button, how do I make an operating system
style call on the server.

Now, I have already figured out how to create a function call in the ASP
development environment that is called when the user clicks on the submit
button.

So my qesttion is to how to create a system level command through ASP.

Specifically, I am using ASP.NET.  Let me explain further.  I have just completed
a program that is very simular to the #3 AJAX demo that Joe Strgner has made on
http://asp.net/learn/ajax-videos/ where he gets users to select from a group
of "CascadingDropDown" control extender classes.  When the user has selected
from the third drop down control, a label is custom formatted and displays the
group of selected options.

What I want to do is this.  After this is done, I want to have a "submit" button
on this page which, when the user presses it, a call is made on the server side
that will include the users selections as parameters.

Something like this, for example:

"CALL SOMEPROGRAM.EXE " selection_1, selection_2

I think I will ask this question in a simpler way.
Notepad is a program that can be launched from the command line.
I can open a CMD window (dos window) and on the command line,
I can type "notepad" and the notepad execuatble will launch and I will
see that program.  So, how would I do that inside asp.net and
specifically inside the Default.aspx.cs file which will get called
when the user clicks on the send button in the function

protected void Button1_Click(object sender, EventArgs e)
{
}

Is there some sort of "run" command in asp.net like "run notepad"?

I also need to have some information specific to the user included in the submit.
We are on an intranet and each user has an alias.  How do I snag this information?