Plus Out Instructions

Given a string and a non-empty word string, set result to a version of the original string where all chars 
have been replaced by pluses ("+"),
EXCEPT for appearances of the word string which are preserved unchanged.

• for input of "12xy34", "xy" → "++xy++"
• for input of "12xy34", "1" → "1+++++"
• for input of "12xy34xyabcxy", "xy" → "++xy++xy+++xy"

Screen Shot of the Test Output