I am trying to find if the entered value is not in a group. Here is my code.

if [ $1 not in ( "LVCH", "LVEI", "LVMI", "LVCH" )  ]
  then
    echo 'Sid is not in list. Try one of these in caps.'
    echo 'LVCH,  LVEI, LVMI, LVCH'
    exit
fi;

This probably isn't the shortest answer but here's one way:

Read in the variable and compare it, one at at time, to your groups. In other words, a nested if/else type of thing. But my guess is that you're trying to find a shortcut and have already thought of this method. If you find an answer before someone else gets back to you, please post it!

Also, I know you can do it with C, but just for comparisons sake, you may want to find a way to take your variable to caps or all to lower, (ie. toupper and tolower in C)

case $1 in
	"LVCH"|"LVEI"|"LVMI"|"LVCH") ;;
	*) echo 'Sid is not in list. Try one of these in caps.'
	   echo 'LVCH,  LVEI, LVMI, LVCH'
	   exit ;;
esac

if [ $1 != "LVCH" ]
then    
        if [ $1 != "LVEI" ]
        then
                if [ $1 != "LVMI" ]
                then
                        if [ $1 != "LVCH" ]
                        then
                              echo 'Sid is not in list.'
                              echo 'Try one of these in caps.'
                              echo 'LVCH,  LVEI, LVMI, LVCH'
                              exit
                        fi
                fi
        fi
fi;