Find a first occurrence of a character in a string in reverse in MSD axapta x++

strNFind  (Find a first occurrence of a character in a string in reverse)

 info("int strNFind(str _text,str _characters,int _position,int _number)");  
 info("Searches a portion of a text string for the first occurrence of a character that is not included in a specified list of characters.");  
 info("_text - The text string to search.");  
 info("_characters - The list of characters to exclude from the search.");  
 info("_position - The position in the string that the search should start at.");  
 info("_number - The number of characters to search.");  
 info("strNFind(\"ABCDE\",\"ABCE\",1,5) " + int2str(strNFind("ABCDE","ABCE",1,strLen("ABCDE"))));