Here is a use of a negative lookbehind zero-width assertion to prevent a split on a comma if it is preceeded by a backslash.

my @array = split /(?<!\\),/, $string;
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It looks like your code is using a colon as the delimiter. This solution can be easily adapted to whatever delimiter or escape sequence you desire.

For more elaborate things, like balanced quotes, you're better off going to a Text::Balanced module, or maybe the DBD::CSV module.

Update: To answer the escaped escape problem that you've mentioned, you could resort to alternation within the split:

my @array = split/(?:\\\\,)|(?:(?<!\\),)/, $string;
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You really end up with some ugly leaning toothpicks!