Look at SSIS (SQL Server Integration Services) which is one of the components of the SQL Server installation.
You should be able to quite easily set up a package which you can schedule to import specific data from one source to another (in your case Excel to SQL Server).
- SSIS on MSDN:
http://msdn.microsoft.com/en-us/data/ff660749.aspx
- YouTube presentation about SSIS + Excel + SQL Server:
http://www.youtube.com/watch?v=79mi31caAag
- StackOverflow "Import multiple Excel files into SQL Server 2008 R2 using SSIS Packages?"
- SqlServerCentral Forum discussion "Import Data from Multiple Excel Sheets using SSIS":
http://www.sqlservercentral.com/Forums/Topic637794-148-1.aspx
HTH,
B