estimating K and Lambda from an extreme value distribution

[Ranjeeva]

Hi All,

I'm trying to fit a set of scores I get from searching  a database of
1000 amino acid sequences with a HMM. I want to calculate a p-value
for each matching score. My questions are

a) How do you estimate the scalling factors K and Lambda to fit my
scores (1000) to an extreme value distribution?

b) How do I then calculate a p-value/E-value from this ditribution for
a given score?

thanks in advance,

Ranjeeva