Hi EAI,
I've had a think about this, firstly switchweapon works on the slot. But because the weapon has to be in a slot for it to work, pressing the shortcut weapon key for the slot would also select the weapon, so in effect say the launcher was applied to slot 2, pressing 2 or G would select the launcher.
Because of this, my suggestion (using the M203 as an example) would be to have a pick up for the M203 rifle and an invisible pick up for the M203 launcher, activated when the rifle is collected. So assuming that the rifle is in slot 1 and the launcher is in slot 2 pressing 1 would enter rifle mode and pressing 2 would enter launcher mode, giving the illusion of a toggle mode. I hope that's clear and would have the advantage of working in all versions of FPSC, modded or otherwise.
I've attached a weapon pick up script and a sample fpm, anyone testing will need model pack 10 to see it in action.
*EDIT* I haven't updated the fpm, but for best results I've added a trigger zone on my own map over the rifle which spans the launcher in it's position.
;Artificial Intelligence Script
;Header
desc = Weapon Pickup
;Triggers
:state=0:state=10
:state=10,plrdistwithin=100:state=1,playertake,coloff,rundecal=-1,plrsound=audiobank\items\pickupweapon.wav,hudshow=weaponprompt,hudfadeout=weaponprompt
;state=2:state=3,playerdrop,colon,plrsound=audiobank\items\pickup.wav
:state=3,plrdistfurther=125:state=10
;End of Script
@milkshape 3d - To the best of my knowledge third person currently does not support player characters holding weapons