Use the DW2 link in my signature to learn how to link to an SQLS database using datasets.
Follow a similar advice but using a connection string from ConnectionStrings.com to get your excel data read into another dataset (using a dataadapter is easier)
Programmaticaly move the data from the excel dataset / tables into the SQLS dataset / tables
Ask the relevant tableadapter to Update() the SQLS dataset/tables
If you dont understand any terms here (like tableadapter; which is NOT a dataadapter) read the DW2 link, section Creating a Simple Data App
You can cut out the programmatic transfer if you can code an SQL to read from the source file into the columns of the SQLS datatable. i.e. your excel reader query might look something like:
SELECT [column0] as PersonID, [column1] as PersonName FROM [Sheet1$]
If your SQLS datatable has columns PersonID, PersonName
...but you will need to use a dataadapter to do the read (you'll probably be doing so anyway)