its as simple as this ...

you = ent_create("yourmodel.mdl",vector(0,0,0),NULL);
you.scale_x=your value;
you.scale_y=you.scale_x;
you.scale_z=you.scale_x;

///pass on any peramiters you like///

set(you,PASSABLE | BRIGHT | TRANSLUCENT):
you.alpha=50;