regex on hash keys?

[Hans Holtan]

Hi everyone,

I'm a bit green, and I'm trying to split a large file into a hash. My 
problem is that the parts that I want to use as keys are a bit long 
(100-200 letters), and I will need to pull them out by the presence 
of certain substrings later. So my actual question is this, how do I 
retreive a slice from a hash based on substrings in their keys?

Thanks for your help.