Question about ships at a shipyard

[Omicron]

ok, im currently thinking about making a mod, i have 0 modding experience, but that doesnt matter, i intend to use an existing shipyard creation script and modify it to my needs, which i think i can handle....

anywho, what i want to know is to do with the number of ships in stock at a shipyard. i need to know how to make it so the chances of a ship being in stock is very, VERY rare, so how do i go about implementing this. this is assuming that ships stock in shipyards is all based on chance anyways...

can anyone who has worked on or looked at the 'create shipyard' script enlighten me as to how i might go about doing this.....

AHMA

[Omicron]

come on!! please, i need help with this!!!
anyone???