Security design help
 

I'm hoping someone can help me with a design issue I'm facing.

I have some Excel macro code that accesses a Sybase database using
standard Sybase logons, and the code gets logon information (server,
database, userid, password) from a clear text file that is currently
stored in the same directory. I'd like to enforce a higher level of
security so that someone cannot just open up the text file and see the
logon credentials.

I'm thinking of using the Microsoft Cryptographic Provider to encrypt
the file, but I think this would mean an encryption password being
hardcoded into the VBA code, and potentially accessible by users. I
suppose I could password protect the module containing the database
access code, but I was wondering if there is a more elegent way of
implementing what I'm trying to do.

Does anyone have a recommendation about how I could enforce security
relatively easily? Maybe setting up the system in such a way that only
the application could read the file (maybe a digital signature or
something?).

Any suggestions would be most appreciated.