Here is an example code snippet. Replace the site address, field names and values to match the form you want to submit. Save the code in a file and save it using vbs (VBScript) extension. Double click on the file and you are done.
Set IE = CreateObject("InternetExplorer.Application")
set WshShell = WScript.CreateObject("WScript.Shell")
IE.Navigate "http://mydomain.com/form.asp"
IE.Visible = True
Wscript.Sleep 2000
IE.Document.All.Item("uselectid").Value = "10001"
IE.Document.All.Item("category").Value = "19"
IE.Document.All.Item("rep").Value = "10001"
IE.Document.All.Item("title").Value = "A new problem title"
IE.Document.All.Item("description").Value = "Description of the new problem"
call IE.Document.Forms(0).Submit()