Help for using Asterisk 1.4.4 plug-in

I have using backticks from FreeSWITCH ( … ackticks.c) on 1.2.17.
Using the astxs to install to asterisk (/asterisk-1.2.17/contrib/script/astxs -install app_backticks.c) and having no problem.
But now i change to 1.4.4, that’s don’t work. Although it’s for 1.2 version. What’s the difference between 1.2 and 1.4 on using astxs for plug-in ?
Any modification needed ? Or is that any new method on execute shell command in dialplan using 1.4.4 ? Please help.

#PS: Error when using 1.4.4 astxs:
make: *** No rule to make target `apps_env’. Stop.

Best Regards,
Sam Ng