Excel parser to replace rows

The objective is to create an ASP.NET C# web page or web application (now called "the solution") that will allow the user to upload an XLS sheet to be processed. Once the processing is done the new XLS file should be downloadable. The XLS source file always contains a column that will have area-codes (also named prefixes or dial codes). The name and index (position on sheet) of that column can change so it is important that either the solution will automatically be able to identify the column or if it fails to do so will present the user with the option to select the correct column (for example via a drop down list containing all column names). The contents of the column will look like this for example: 24566;24587;24690-24692;36654 The solution should then replace this particular row with 6 rows. Those new rows would have the following prefixes: 24566 24587 24690 24691 24692 36654 If you have any questions, feel free to ask.