Say you need to sudo as a particular user and run a command and at the same time you need to pass an environmental variable to the command, you can do it by passing the command in doublequotes.
For example, I want to start Oracle while I am logged in as another user (vinay), I can start the database using dbstart by issues
"sudo su - oracle -c "dbstart /$ORACLE_HOME"
$ORACLE_HOME is an environmental variable listed under user oracle’s environment.
Needless to say, you need to ensure that you have sudo configured to allow your userID to su to oracle.