Automatic determination of character default

Dear gurus,

I would like to determinate a default automatically when I input a characteristic value.

For exemple, during results input :

If 1 < characteristic value < 2 then assigning automatically no default (or Q1) - ratio = 100

If 2 < characteristic value < 3 then assigning automatically default Q2 - ratio = 90

If 3 < characteristic value < 4 then assigning automatically default Q3 - ratio = 80

If 4 < characteristic value < 5 then assigning automatically default Q4 - ratio = 70...

Is it possible to define that in QM by a standard way ? By using a dynamisation rule ?

Thank you for your help.

Christophe