How to pin a control panel item to start?

First we need to create a short-cut to Network Connections.

1. Right click on an empty area on the desktop, and click on New and Shortcut.
2. Copy rundll32.exe shell32.dll,Control_RunDLL ncpa.cpl into the location area and click Next.
3. Name it Network Connections. and click Finish.

That will do it, but you can change the icon to a network icon by the following:

1. Right click and select properties of the Network Connections shortcut and select Change Icon.
2. Copy "%SystemRoot%\System32\netshell.dll" for the path to "Look for icons in this file."
3. Select your icon.

Source

Now you just need to right click and pin your shortcut to Start.

I know this has been already solved but, there is a much easier way to achieve this.
You can create a Shortcut to Network Connections by typing control ncpa.cpl in location field in New Shortcut Creation Wizard and you are done.

Syntax is control <any item from list>.cpl.
This syntax can be used with Run to access a lot control panel items easily.

PS: C:\Windows\System32\control.exe ncpa.cpl can also be used as location.

Currently, there isn't a way to "pin" various Control Panel items onto the Start screen.

The best that you can do is view "Administrative tools" (Win + C --> Settings --> Tiles --> Show Administrative Tools) which contains a few more applications within the Start screen, but not specific areas of Control Panel.