If the SQL Server Express is set up correctly (meaning it allows access
from other computers), you simply start your MS Access and click menu
File->Get External data->Link Tables...(or Import, if you you want import
data from SQL Server one time only). On "Link" or "Import" file open
dialog box, go to "Files of tpe" dropdown list, select "ODBC databases()",
which lead you to "Selct Data Source" dialog. Continue on to create new
ODBC data source/select existing ODBC data source, which connects to SQL
Server Express. Once all this done, you have a Access *.mdb file that
links to SQL Server database.
BTW, this NG is for Access ADP project, not *.mdb linked Access front end.
You may go to microsoft.public.access to get better responds to your
questions