Here's an explanation of the syntax:
Replace («stringexpr», «find», «replace», «start», «count», «compare»)
Where
stringexpr = the starting string or field value
find = text value / string to search for
replace = replacement string / text value
start = starting position in stringexpr (1 to begin at first character)
count = # of occurrences to replace (2 in this case)
compare = method used for comparisons (0 is use database defaults)
Denis