how to redirect to “page not found”

Question

how to redirect to "page not found" for code in SharePoint 2013?

To page /page/PageNotFoundError.aspx

Does anyone knows how can I do that?

example:

item.status = rejected
then this.page.redirect = pagenofound.aspx

the page exists, I just need to go to it, for code, following given conditions

Answer 1

You can update the default 404 page for the webapp using powershell

$webapp =Get-SPWebApplication http://<SiteUrl> 
$webapp.FileNotFoundPage = "custom404.html" 
$webapp.update()

Source: http://www.spdeveloper.co.in/articles/pages/custom-page-not-found-page-sharepoint-2010.aspx

Answer 2

I was looking for something as this

Anyone have a link showing how to do this in shp2013?