Damsel in distress!

Hi clever people!

This is my first day on here- I work for a design company and our Web guy has unfortunately traveled to pastures new-leaving me to try and sort out some of the web stuff!!! I have a very beginners based knowledge of the web-i.e I have dabbled in Flash and dream weaver-but I could do with a quick question being answered…
We are producing a fun site for a theatre that are showing the wizard of Oz and they want an online game (splat the witch!)…we have a flash game that we produced a while ago for our company(splat the staff with cr*p!) so we are going to modify this-however they would like to add an online scoring system to this -so they can make it into a competition. I’m taking it that an online scoring system will have to be built into the flash game itself-but I need to know if this is a complex job and how long it would take-just so I can factor it all into the budget.

I would really appreciate some help and advice on this-many many thanks!! x