I've not run into problems with CPAN on win32, so I can't really help all that much.
First thing you need to check is your path. You said you had c:\perl\bin there, but I'd double check.
Secondly, you need to check your config.pm in c:\perl\lib. I'm not a big fan of the active state installers. Build 522 set up all my paths as \\peterj\perl\whatever instead of c:\perl\whatever. This didn't appear to break anything, but did cause a lot of warning messages.
I had to roll back to build 522 for compatability with the PDK, so I can't try this on a 5.60 version, but Number::Spell installed just fine using nmake on my system. And I didn't have any problems when I was running build 613.
If all else fails, you can try to copy the Spell.pm to C:\Perl\site\lib\Number\Spell.pm
--Shoeboy
perl -e "do {kill $java, $ada, $cobol, $pascal, $csh;} until die 'Just another perl hacker';"