Custom Configuration management for app.Config

Hi,
I created a custom Section handler using System.configuration for Web
application to read from Web.Config File.

If I want to use the same handler to read from app.config file:
app.config is not interpreted as XML file, & the code breaks.

Here is the sample of the logic.

For Each node In section.ChildNodes
For Each element In node.ChildNodes
elementKey = element.GetAttribute("key")
elementValue = element.GetAttribute("value")
Next
Next

Kindly let me know how to use the same custom handler to read from
web.config as well as app.config file.

Thanking you
Shaun