This function allows you to find the offset position (base 1) of the matched instance of your regular expression. It is similar to the at() function but is more powerful as you can use a regular expression for your match and you can also specify the matching instance number. If there is no match for that instance the function will return 0.
sExpression - The regular expression to match sData - The data string to search for sExpression sNumber - The found instance
Examples:
#find offset of second match of "cat"
$pos = regexpos("cat","my cat is a very fat cat!",2)
msgok msg=$pos
#find offset of first match of "cat"
$pos = regexpos("cat","my cat is a very fat cat!",1)
msgok msg=$pos
