Is your SQL code part of a SP?

Who calls that SP, is it interactive or not?

Depending on your situation, you might have some of the following options:

a) Call your SQL code from an application written in a compiled language (e.g. C++) or, at least, C#,

hard-code the password there and pass it to your SQL code.

b) Write an encrypted SQLCLR UDF that will just return your hard-coded value.

If you are in SQL Azure, the V12 version has support for SQLCLR:

http://azure.microsoft.com/blog/2014/12/11/preview-available-for-next-generation-of-azure-sql-database

https://msdn.microsoft.com/library/ms189524.aspx