The only way to do this is to create a lib.
The gist of it is: You need to create a remoteview and assign the notification contentview to the remote view.
In theory it looks simple. In practice, there are a lot of things I do not understand regarding B4A's handling of these objects.
I already got into trouble the first time I did this (do a search), so I am not going to attempt it. Besides my attempts failed and you might need to go too deep and create your own notifcations wrapper instead of using a quick hack.