'Position_Enemies()' function...?

Ok, I'm starting the enemy/AI coding part if my game and I need some help. Basically, I need some enemies that will form different formations like 'V' or 'Line' etc. I'm probably going to do this with functions [duh], but how do I write it so that I can change the ammount of enemies etc. ie.

function form_V(ammount#,xpos#,zpos#) 
???????????????? ;the part i need help with lol
end function

ok, now I call the function...

form_V(5,0,50)

...And te enemies should appear on the screen like this:

V-------V
--V---V--
----V----

Or if i called 'form_line(5,0,50)' the enemies would appear on screen like this:

V V V V V

Does anyone have any ideas? Please help me with this...Ps, im using types to do this...