can boomerang use range combat expert against sandman if sandman is base to base with boomerang?

According to the FAQ the only way you can use RCE with B2B is this:

• A hovering character that is adjacent to an opposing character may make a ranged-combat attack, but only against the adjacent character.

:AND:

• Grounded characters may perform ranged-combat actions against adjacent hovering characters, but only if they are not also adjacent to any opposing grounded characters.

No. You can only use ranged combat expert in base to base if one or the other ,or both figures are fliers.

thanks guys. very helpful