Two methods I can think of ...

# method 1
print qq{@{[ map { ucfirst} $c =~ /([^_]+)/g ]}};

# method 2
$c =~ s/([^_]+)|_/ucfirst $1 or ' '/ge;
print "$c\n";

# method 2 - updated version
# just realized there might be a problem if the pattern
# $c = '0_a_c_code', where 0 also evaluates to false

$c =~ s/([^_]+)|_/defined($1) ? ucfirst $1 : ' '/ge;
print "$c\n";
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