Formatting numbers

Hi! Is there a function for formatting numbers by inserting characters like , and .? If there isn't, does someone feel like writing it? :) I have something like the following in mind: str_format_number($number, $character, $every [, $maxnumber]) To illustrate what it would do, here are some examples: str_format_number(10000, ',', 3) := "100,00" str_format_number(12345678, ',', 3) := "123,456,78" str_format_number(12345678, ',', -3) := "12,345,678" str_format_number(1234567890123, ',', -3, 2) := "1234567,890,123" str_format_number(12345, '.', -2, 1) := "123.45" str_format_number(1234567890123456, ' ', 4) := "1234 5678 9012 3456" $number is the number to format $character is the string to insert $every specifies how many numbers to group together. Negative $every means the function should start at the end. $maxnumber is the maximum number of $character's to insert.. thanks, Mitja