The following part from cerberi_croman's code should already stop the player from 'floating' beyond the point you clicked:

if(vec_dist(my.x,temp2)>=40)
{ c_move(me,vector(7*time_step,0,0),nullvector,IGNORE_ME|IGNORE_PASSABLE|GLIDE);
}

This means, the player only moves as long he isn't closer than 40 quants - that's a reasonable distance for the size of normal models - maybe the size of your model is much bigger. Play with the value, make it larger, 100 or 400, just to get an idea when the player stops walking.