It's pretty easy -- but there are a couple of rules: no spaces and use absolute paths (put the slash in front of home).
So
cd <this gets you into your home directory>
vi .bashrc <this file may or may not already exist>
EGS_HOME=/home/user78/egsnrc_mp
EGS_CONFIG=/home/user78/HEN_HOUSE/specs/i686-pc-linux-gnu-g77.conf
export EGS_HOME EGS_CONFIG <assuming HEN_HOUSE is already defined!>
Save the file.
Log out, log back in, and you'll have those variables set in your environment. To see them,
echo ${EGS_HOME}
echo ${EGS_CONFIG}
Also, take a look at "man bash" about local or personal initialization files (.basrc is one).
