Try to named your frames and then use examples from help to combine animations. Just play 0-100% walk animation and f.e. 20-60% mounth animation.
define _mouth_speed,skill10;
define _walk_speed,skill11;
while(1)
{
clamp(my._mouth_speed,20,60); //talk animations 20-60%
my._mouth_speed += 1 *time_step;
my._walk_speed += 2 *time_step; //play with those speeds
ent_animate(me,NULL,0,0); //reset animation
ent_animate(me,"mouth",my._mouth_speed,anm_cycle); //add a bit to last frame
ent_animate(me,"walk",my._walk_speed,anm_cycle + anm_add);
wait(1);
}
But it's only sugestion... right know I don't have a vertex animation model to check this out. And no idea if this will work
Better idea is to import with bones from 3ds