Can I create some extra animations (instead of "walk", "stand", or "death", "walkCarryingGun"?) and then execute them in script?

Of course you can name your animations as you want, you just have to number them ("go1,go2,go3,go4;attack1,attack2,attack3,whatever1...). You have to start with 0 or 1 (depends on engine version or it doesn't matter). In script you can use the animation names with ent_animate or ent_cycle

You also can access the frames directly by using entity.frame

For example:

if(my.frame <= 30)
{
my.frame += 1 * time;
}

Its a bit more complicated than using ent_animate or ent_cycle but it works

aaron1a12e: I'm not sure where you got your copy from. But if you paid money, you've been ripped off. Demand your cash back or get legal help.

The illegal version of 3DGameStudio DOES NOT WORK.
Please do not ask for help, you will only get into legal trouble.