There are no DFCMs installed on M777s because they proved to be a security risk on the first few days. It can’t be used with smart munitions without it. HIMARs can fire GPS-guided munitions but they aren’t “shells”.
Picky troll these days - nothing better to do? Aren’t there some small children in your neighborhood you could harass and steal candy from?
If you’d kept up, which being a nasty Ruzzian you would not know how, they were supplied some months ago with the needed guidance units - of slightly different design, but just as effective - as well as GPS munitions for them