EUR-Lex - http://eur-lex.europa.eu/en/index.htm - contains all COM docs in full from 2000 onwards and selected ones from 1999. Select Simple Search, then Preparatory Acts.
Some COM docs are published in the Official Journal C series.
Subscription-based
databases
Justis EU - select Celex from the Data Sources list. Tick Proposals and enter year and number in the Document Typefield.
Lawtel EU - search under Proposed Legislation.
Westlaw UK - in the EU database, enter the COM doc number in the Document Number box.
They are numbered sequentially each year and are referenced by number and date i.e. COM (2002) 0018.
Note that the COM doc number is often seen in the format COM (2007) 368 final - the word 'final' indicates that this is the version formally adopted by the Commission.
