Scaling of a notch filter Let's say I have an IIR filter that is a notch type with a peak at -20db. How do I modify the coefficients of the filter so that the peak is at -10 db for example?

I know I can scale the denominator coefficients so that the global peak amplitude can be set, but it affects the whole filter, which I don't want. 

Here is what I want :
You show a pretty narrow notch, are you trying to notch out a tone? If so, maybe you could use an Inverse Chebyshev, and move the -10 dB pt in the notch to your tone frequency.