Percentage discount based on qty

Hi- We have a requirement to limit discount condition by qty. I mean we wanted to give 10% discount for the first 100 qty of sales order. We could not use condition update functionality by qty when the calculation type is percentage. We could not use field Max Cond value as it depends on other condition types at the time of sales order. Unknown factor for us. We are not able to use condition update when the discount cal type is qty. I am trying to find anyways to update S071 and any formulas for these % condition types.Any ideas to implement this will be appreciated.

Send me the code if anyone uses this using scales.

Reg

Shan1242