If new means "in addition to existing stuff", then you need to add a line in appearances.2da. See below the example for the NWN dragons I ported to NWN2 (I know, they haven't been released yet: there are some attacks and dodge animations I need to finish):
2094 Dragons,NWN **** 1 0 1 1 1 1 c_nwndragon c_nwndragon c_nwndragon_head **** c_nwndragon_skel c_nwndragon_skel 1 **** 0 0 Dragon_NWN c_Dragon **** 3 FWT 1 1 1 1 1 FAST 3.33 3.33 2.5 2.7 1 2.5 6.5 H 1 11 1 1 po_DrgGreen 5 10 2 22 0 60 30 Dragon_head 3 1 0 10 ****
Dragons,NWN is the name that will show in the dropdown list when you select the creature appearance,
c_nwndragon is the short name of the model (the engine will look for c_nwndragon_CL_body01)
c_nwndragon_head is the name of the head model (head, tails and wings can be changed, or even not used, for this series of dragons)
c_nwndragon_skel is the name of the skeleton used by c_nwndragon_cl_body01: with a new skeleton, there's no overriding the existing animations, so I could create a full set of different animations for these dragons.
On the other hand, if you're still using P_HH?_skel, the only way I found to add new animations without overriding existing ones is to create customs animations (the problem being that you'll have to write a lot of AI scripts to force the engine to use the new combat animation. Besides, I'm not even sure this would be possible for walking and running).
The way I understand your question, you're probably in the first case. If you used P_HH?_skel, just rename it P_PA?_skel (for Psiiijay Animations
) and resave your animations with the correct naming conventions (P_PA?_1hs_1attack01 for the first variant of the sword or similar weapons without shield for P_PA?_skel, P_PA?_D2h_walk for the walk animation when carrying one weapon in each hand, etc...)
Don't forget though that all the standard armour models (including gloves, helmets, cloaks, boots, etc...) need to also have a P_PA?_skel variant if you want your new mode to use the stock equipment...