I have database in the web with SQL Server 7.0. Now how can I periodically update the content of the database by simply uploading text file containing the cumulative updates?

Can anyone help?

Since the access is over the web you're not going to have access to BCP or DTS. I'm assuming that this is done for some kind of hosting arrangement. You might want to check with your ISP to see what types of tools they offer but your best bet is probably going to be for you to write a small program in whatever languages they give you access to.