nothing within SQL. SQL doesn't do files, technically.
SSIS or SSRS subscriptions can export data to native excel format.
otherwise, not really.. you have to use something external, like a CLR, Excel automation via sp_OaCreate, or third party dll or application.
if you have an existing template excel file, you could use a linked server to connect to it and insert/update/delete rows in that file.
if the file headers are dynamic, i'm not sure what you would do.
Lowell