Question

I am developing an app for windows 8 , in which I want the toast to have link to any webpage or any other metro application rather than the own application.
note:The web link or App Name will be entered by the user.

Answer 1

This isn’t supported. Toasts can only take the user to the application that sent the toast. See below.

From MSDN:

A toast notification can contain text and/or images, but secondary
actions such as buttons are not supported.

and

When a user taps or clicks the notification, the associated app is
launched and the user can expect that the resulting view is related to
the content of the notification. It is the only mechanism by which one
app can interrupt a user in another app.