Just for the record, as i have been digging about this same thing, without finding a clear answer anywhere.
As translation texts are not copied copying only the status, as hinted somewhere else, you can copy the whole function group into a Z (without the methods).
Then in the new Zfunction group you can create copies of the standard status adding your customer needs (new menus/buttons), and translating just the new items (for use in external programs).
Then when creating your alv reports instead of using status from its own program, use the status from this Zfunction group.
(Using "CL_SALV_MODEL_BASE->SET_SCREEN_STATUS" you can use status from other programs).
Cheers