Never tried it myself but found this in the forum:
Code to insert in Manifest:
AddActivityText(main,
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="text/x-vcard" />
</intent-filter>)
Replace mime-type with your extension.
Then in your app you need to act on the request somehow. Again a search in the forum showed this
thread:
As I said, I never tried it but it may get you going in the right direction.
Hope this is what you're looking for...