link to itunes from webapp ?

I have a scenario where I need to link to a app store application to be downloaded from an webapp is it possible ? something like href with application id ?

or is it possible to launch app store with a particular application shown up in it from my native application ?

better still, is it possible to use some kind of itunes library or appstore library to download apps from my native app, through in app purchase ?

--CH

 

no body tried it ?