If this is an application ID, I have a solution for you. This is not my script, but I offer it to you.

Set your login shell to /usr/bin/nologin for this shared user.
Next, login as yourself then su - username.

Use a script, put this in your .profile for the application, like this one below to keep track of individual history files.

When you su to root or an application ID this is great! Remember put this in your .profile for root or application .profile.

#***************************************
# sets .sh_hist file to id of user

if [ "`tty`" = "/dev/console" ]
then
REAL=console
else
REAL=`logname`
fi


HISTFILE=$HOME/.sh_$REAL
export HISTFILE
HISTSIZE=1000; export HISTSIZE
#****************************************