creating tables with different character set?

hi,
i have a problem. i'm living in poland, which has its national characters. of
course they work great under postgresql, but:
when i use non-C locale all ~ '^xxx' and like 'xxx%' searches are not using
index scan.
this is paintful.
for some of the tables i dont need all national characters. in fact i use only
a-z0-9 characters which are subset of standard C-locale character set.
so my question is. is it possible to make a table that way, that it will allow
using indexing when searching for first x characters of string.
at the moment the only solution i got is to make another database (with another
postmaster process), but this is definetly not easy way.
any other options?

depesz

--
hubert depesz lubaczewski http://www.depesz.pl/
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najwspanialszą rzeczą jaką dało nam nowoczesne społeczeństwo,
jest niesamowita wręcz łatwość unikania kontaktów z nim ...