security flaw?

Hello all, As part of my website, I need to allow the users to upload data from an access db to my mysql db. This is all done with a small delphi utility by way of odbc. The problem is, my webhost will only allow me to have one user set up for the db so when I set up the odbc connection for the client (by way of an install), I have to set up the main username to the db and the main password. When I go back into odbc, the password appears to be hidden from the user but is it really? How can I give them access into this table without such a security risk? Thanks, Eddie