pattern - An attribute of base type string or a string value. String must be a valid regular expression. The regular expressions used in several Blueriq Encore functions are common Java 1.4 expressions. For a complete documentation we refer to the online java documentation.
string - An attribute of base type string or an expression that results in a string.
startIndex - A positive integer value indicating at which character of the string the search should start (inclusive). This can be either an attribute of base type integer, an expression that results in an integer or a constant integer value. The first character starts at index 0.