With 1 keyclick u can switch ur weapon in ur left or righthand.

How?
type in ur console the next line: bindToggle [name of key] cl_righthand

Mine is bindtoggle V cl_righthand

if u want to change this in ur config.cfg: put this line there:
bind "v" "incrementvar cl_righthand 0 1 1 (thats the result of typing bindtoggle V cl_righthand in the console)

Everytime i click V the weapon switch. And i like now to play with my gun in my lefthand :)

Give it a try.....