After a long holiday, Agent Nikita was called upon to embark on a new mission. Her boss, "Big Bro", asked her to go to Paris where she would meet another secret agent. This agent would guide her further in her quest. She checked in to Glitz, an expensive hotel in Paris and waited for further information. At midnight, a stone with a piece of paper wrapped around it came crashing in through her room's window and her mobile phone rang. Her mobile screen displayed "Private Number". She stuttered and answered the call with a shaky "Hello". The caller answered, "Hi! On the paper covering the stone is a clue. Substitute the letters with digits from 0 to 9 such that they make the relation true. Make sure that each digit is represented by only one letter. You can spell out my codename by arranging the letters from left to right in the order "0 to 9". I can't tell you my name for fear that this call is being intercepted. I shall meet you in the Coffee Shop of this hotel at 3 pm tomorrow. Our password shall be my codename. Don't be late. Bonne nuit!" Saying so, he hung up. Agent Nikita unwrapped the paper and carefully went through the note.
Help Agent Nikita figure out the name of this "Mystery Midnight Caller". Provide a detailed explanation along with your answer.