Using
void DuplicateHeadAppearance(object oidCreatureToChange, object oidCreatureToMatch);
You'd need to create two dummy UTCs, one male, one female, each equipped with the glass and null blaster and with the Proficiency All feat. Then under a fade to black you'd jump the PC somewhere out of sight and spawn in the fake of the appropriate sex, clone the PC's head onto it and duplicate their equipped armour/robes/clothes. The meat of your script could look something like this:
object oPC = GetFirstPC();
object oFakePC;
object oBodyItem = GetItemInSlot(INVENTORY_SLOT_BODY, oPC);
location lSpawnPoint = Location(Vector(1.1,2.2,3.3), 0.0);
if (GetGender(oPC) == GENDER_FEMALE)
{
oFakePC = CreateObject(OBJECT_TYPE_CREATURE, "FAKE_PC_TEMPLATE_FEMALE", lSpawnPoint, FALSE);
}
else
{
oFakePC = CreateObject(OBJECT_TYPE_CREATURE, "FAKE_PC_TEMPLATE_MALE", lSpawnPoint, FALSE);
}
if (GetIsObjectValid(oBodyItem))
{
object oNewOutfit = CreateItemOnObject(GetTag(oBodyItem), oFakePC, 1);
AssignCommand(oFakePC, ActionEquipItem(oNewOutfit, INVENTORY_SLOT_BODY, TRUE));
}
DuplicateHeadAppearance(oFakePC, oPC);
Then once that scene is done, under another fade to black you destroy the fake PC and jump the real PC back into position. Obviously this only works for pure cutscenes. You can't do it for a conversation requiring PC responses (at least during this part of it).