Difference between director & managing director

Managing Director means a person who, by virtue of an agreement with the company or of a resolution passed by the company in a general meeting or by its Board of directors or by virtue of its memorandum or articles of association, is entrusted with substantial powers of management which could not otherwise be exercisable by him and includes a director occupying the position of a managing director, by whatever name called. The power merely to do administrative acts of a routine nature, when so authorised by the Board such as the power to affix the common seal of the company on any document or to draw and endorse any cheque on the account of the company in any bank or to draw and endorse any negotiable instrument or to sign any share certificate or to direct registration of share transfers will not be deemed to be included within substantial powers of management. The managing director must exercise his powers subject to the superintendence, control and direction of the Board. 
 

What would be the procedure if we want to elevate a Director to Managing Director , and what forms are required to be notified the same to  ROC