Moving in Formation, etc. (RTW)

Much to my chagrin, I once again find my self unable to effectively command large forces in a Total War game. When I deploy my army into a custom formation - let's say, for the sake of argument, archers in a thin line at the front, then heavy infantry, then cavalry off-centre, then light infantry in reserve - then select them all and order them to move approx. a bow's shot from the enemy army, they all just mass up into one big mish-mash of a line. How do I prevent this?

Also - how do I order my archers to stop firing (used when the melee has been joined and I don't wanna hit my own guys). I've tried both disabling 'Fire at Will' and hitting Halt, but neither seems to have any affect.

The only way I have found to do this is to group the whole lot that you want to keep formation and then move - you can also use the "drag/click" to position it at a different axis

Bearing in mind i dont have the full game and am using the RoDeO mod for the demo i havent found this to be a problem.
I usually ALT A to select the whole army and number it 1 and then select the formation i require and let them form up in that formation.Bear in mind that when you order the whole army to move they sprint at first which makes the army look ragged and then it seems to regain its shape as its marching,the use of the space bar confirms their finishing position.
Also as Colovian says you can adjust the facing of the army as a whole using the ALT and right MB to make any adjustments by dragging the mouse around until you get the positions/facing you want.
What was initially a bit of a problem for me now feels quite intuative and comfortable to carry out.It just took a little practise in a non combat enviroment (as attacker in the demo) to get used to it.

Regards....

I always drag click when i tell my men to move. Also, if you dont want to waste time on this group your men using the group button or ctrl+(1-9) and then use the formation buttons. I tend to group my men before the battles. Happy hunting