[str] = "xyz+=/"
REGEX_Replace([str], "/", "%2F") = "xyz+=%2F"
REGEX_Replace([str], "=", "%2D") = "xyz+%2D/"
REGEX_Replace([str], "+", "%2B") = null
In the above, replace works fine unless you are trying to replace the character "+" -- there doesn't seem to be a way to escape the character either, why?