Hi,
I would recommend to use it as a "web part". In this case, the news list web part in portal engine is just inherited from the repeater web part/control and named "News list".
So, in the ASPX templates you can use CMSRepeater control and just configure it to list the news.
You can find the web part's code in CMSWebParts folder. these code files are also used by the portal engine web parts. Some of the web parts are using/based on some server controls. These controls are usually in CMS.Controls assembly. you can add these controls to the
Visual studio toolbox.
Best regards,
Juraj Ondrus