Yep sure, you need to find the unit entry for the bodyguard in the EDU
Code:
;503
type             hellenistic cavalry pontos late bodyguard
dictionary       hellenistic_cavalry_pontos_late_bodyguard      ; Pontos Late Bodyguard
category         cavalry
class            heavy
voice_type       Heavy_1
soldier          hellenistic_cavalry_hetairoi_molossianagema_ponitclatebodyguard, 10, 0, 1
mount            hetairoi companion horse
mount_effect     elephant -1, chariot +2
attributes       sea_faring, general_unit_upgrade, hide_forest, hardy
formation        1.5, 4, 3, 6, 3, square
stat_health      1, 1
stat_pri         5, 44, no, 0, 0, melee, blade, piercing, spear, 200 ,0.4
stat_pri_attr    ap
stat_sec         11, 25, no, 0, 0, melee, simple, slashing, sword, 0 ,0.11
stat_sec_attr    ap
stat_pri_armour  15, 12, 0, metal
stat_sec_armour  0, 0, metal
stat_heat        4
stat_ground      0, 0, -4, -2
stat_mental      18, disciplined, highly_trained
stat_charge_dist 30
stat_fire_delay  0
stat_food        60, 300
stat_cost        1, 2122, 0, 100, 160, 2122
ownership        carthage
and change the mount line to read "hellenistic kataphraktoi horse", I think thats all you need to do. Good luck