Key assignment to Home key & Differentiating between arrow keys on numeric and cursor key pads

I've been reassigning values to various keys, to recreate a navigation keyboard I have used in WP5.1, WP 8, and later in other programs. In my recently purchased (from Corel directly) WPX7 I cannot find the Home key in Settings / Customize / Keyboards. Can someone please tell me if there is any way to circumvent this bug (if bug it is)? I need to be able to assign new values to Home and Ctrl-Home. Can I somehow bypass the keyboard editor and edit key values directly (e.g. in the Registry or an INI file)?

Also: Is there any way I can differentiate between the arrow keys (and Home, End, Insert, Delete, Pg Up/Dn) on the numeric and cursor keypads when redesigning my keyboard? In other words, can I attach different values to e.g. the Left key on the numeric keyboard and the Left key on the cursor keypad? This was possible in WP5.1, but not (I think) in WP8 (though maybe I just never figured it out).