select month and Year inC/odbc - MS Query

When I use the C/ODBC link to Excel, I am unable to group by month. In MS Query I’m editing the SQL statement, but I’m unable to pick out the month and year from the date field. When I worked on an Oracle database I could select characters from a text string with the command SUBSTR(field,start_position,number_of_characters). I cannot get this to work. Please advice how I in MS Query can select a year and a month so I’m able to set criterias and group by period. Regards Frank