Host Variable in dbaccess sql script.

Is it possible to create a SQL statement with HOST Variables within the script. Here is an example of something I am wanting to do: USER=TWRIGHT select xuser from xcp where xuser = '$USER'; I am running this script from the command line by doing: dbaccess -e database user.sql. It appears to run but DBACCESS converts the host variable USER which is TWRIGHT into twright. The user is not in the system in lowercase but uppercase. Can someone give me a few pointers.