Question:
Which position did Henri Longchambon hold in Apr, 1950?

Context:
 Henri Longchambon holds the position of Representative of the Parliamentary Assembly of the Council of Europe from Aug, 1949 to Sep, 1952. 
 Henri Longchambon holds the position of Substitute member of the Parliamentary Assembly of the Council of Europe from Sep, 1952 to Apr, 1959. 
 Henri Longchambon holds the position of director from Jan, 1938 to Jan, 1940.

Answer:
Representative of the Parliamentary Assembly of the Council of Europe