You can only use SELECT statements in the Command text.  You can't update the database from Crystal in that way.

Though, as a note, if you put a stored procedure in your database, that stored procedure can do anything any other stored procedure can do.  And, you can make any stored procedure the data source of the report, even if it doesn't return any records.  So, you could create a stored proc that does this.  (I'm guessing, though, that you are attempting to do it this way because creating a new stored proc is not a possibility for you.)