Dealing with passwords in SAS is a complete pain in the backside.
The only recommendation I can give you is either to use PROC PWENCODE (you'll need to read up on it in the online documentation for the full use of this), OR talk to your IT people and see if they can come up with a secure method of storing the passwords etc.
I think the best method we came up with was to have a username and password which had only the access it needed to load the data and nothing else, and protect the password as best we could (restricting the access to the SAS code so that only I could actually read it). I would suggest combing this with PWENCODE, as PWENCODE isn't particularly secure. It stops users getting the password and then using it to log in, but doesn't stop them from copying and pasting it into their own code and using it there.
Chris
Business Analyst, Code Monkey, Data Wrangler.
SAS Guru.