If by "command sequence" you mean you want to add this to one or more specific commands, adding these actions at the bottom of the action list should do what you're describing:
Set decimal [~rand] value as random from 0 to 1
Begin Decimal Compare : [~rand] Is Less Than 0.0050
Switch to profile, 'profile 2'
Else If Decimal Compare : [~rand] Is Less Than 0.01000
Switch to profile, 'profile 3'
Else If Decimal Compare : [~rand] Is Less Than 0.1000
Switch to profile, 'profile 4'
End Condition