How to give dialogue response a random chance at NPC action?

[Lauriel]

I have a dialogue between the PC and a 'bounty' NPC.  There are three things the PC can say to the NPC:  like the following:

    IF ~whatever~ THEN BEGIN Quest1
        SAY @2220 /* ~You?  What do you want?!~ */
        ++ @2191 /* ~(in my best Schwarzenegger voice) Come with me if you want to live.~ */ + Quest2
    END

    IF ~~ THEN BEGIN Quest2
        @2210 /* ~So my choice is the noose or death by a terminator?~ */
        ++ @2211 /* ~If I choose to reply with this option, I want the NPC to have a 50/50 chance of saying 'Die Sucka!' or 'Ok Fine. I quit!' ... or something to that affect.~ */ + Quest3a
        ++ @2212 /* ~If I choose to reply with this one, they will surrender.~ */ + Quest3b
        ++ @2213 /* ~If I choose this one, they will attack~ */ + Quest3c
    END

So, how do I do the 50/50 thingie?  Do I have to do a cut scene with the a RESPONSE #50 ... #50 and have it go back to the dialogue or can I somehow do this within a dialogue?

[The Artisan]

+ ~RandomNum(2,1)~ + @2211 /* ~If I choose to reply with this option, I want the NPC to have a 50/50 chance of saying 'Die Sucka!' or 'Ok Fine. I quit!' ... or something to that affect.~ */ + Quest3a1

+ ~RandomNum(2,2)~ + @2211 /* ~If I choose to reply with this option, I want the NPC to have a 50/50 chance of saying 'Die Sucka!' or 'Ok Fine. I quit!' ... or something to that affect.~ */ + Quest3a2

[Lauriel]

Perfect!  Thank you @Artemius I!