When I import the ASP.NET page into Visual Studio 2003, it complains about SRC=.

You have to delete the SRC-attribute. Visual Studio 2003 uses CodeBehind instead.

You find a tutorial here:

save-asp-net-to-database-14.pdf

A little article describing the difference between Src and CodeBehind:

http://www.dotnetcoders.com/web/Articles/ShowArticle.aspx?article=22

Visual Studio is too expensive, any alternatives?

If you do not want to purchase VS, there are free alternatives.

Microsoft® Visual Web Developer® 2010 Express provides you with everything you need to start building standards-friendly Web applications

http://www.microsoft.com/express/Web/

How can I store the form values in a database?

You want to store the values from your ASP.NET form into a database and repopulate the form when the user returns back.

Connecting an ASP.NET form created with SpreadsheetConverter to a database is very easy if you know some programming and Visual Studio.