Media Composer only accepts an ALE file for import and merging into existing clips. An ALE file is a somewhat enhanced TAB separated file in the fact that it contains a header and a separates of columns versus data. You need to convert that CSV into a TAB file, usually in Excel, and then in a text editor, remove all the extra TABs that Excel like to add and make sure the last event has a return character. I usually do this in TextWrangler while viewing invisible characters. Once all this is done, and the header is appropriate for your project type. Somewhere out on the Avid site is a whitepaper on ALE creation and metadata logging and management where there is a section on creating ALE files.
Michael