Use the mmioCFChangeEntry function to modify a CTOC entry in an open RIFF compound file. The mmioCFChangeEntry function requires a pmmctocentry parameter which identifies a pointer to a user-supplied CTOC structure containing modified CTOC data. The "identifier" for the entry is the element name, which is passed in the pmmctocentry buffer. The mmioCFChangeEntry function updates the CTOC entry with the information contained in the user's pmmctocentry. If you change the compression technique, you must also modify the ulUncompressBytes field. When the compression technique is NULL, the uncompressed bytes field must be the size in bytes of the element when it is uncompressed.