create custom collation from case insensitive portuguese

Thanks to all the work they have done with this incredible database, 
postgresql.

I've achieved some success in changing collate operating system (linux) 
to generate sort of way of Brazil Portuguese hopes by adding the 
following code in LC_COLLATE

LC_COLLATE
copy "iso14651_t1_ci"
reorder-after <U00A0>
<U0020> <CAP>; <CAP>; <CAP>; <U0020>
reorder-end


And in my tests I could change the behavior of the postgresql UPPER 
changing the file i18n ... etc.

toupper /  (<U0061>, <U0041>);


So far, I understood the mechanism of change collate and reproduce in 
postgresql, and I could not generate a case-insensitive search, I 
believe that would change within the LC_COLLATE variable, but could not 
go any further than that.

Could someone guide me please.

Thanks,

Alexandre Riveira
Brazil