Adding a executable file $PATH Variable

Hello Linux Guru's

I am having a problem in adding a executable file to $PATH and getting it worked.

I am adding an executable file to ~/bin directory from my shell script.Now,from my understanding it should be available for execution,outside of the subshell.
But,after running shell script,I am unable to execute that command,until i issue rehash command to rebuild it's hash table.I am using tcsh.
My Requirement is that,Just after running my script,command should be available for execution,without execution of any extra command.I am using Solaris and tcsh.

Please provide any working solution, because of this i am stuck in my project.

Your requirements are not compatible with tcsh. Tcsh doesn't update its path contents cache until the rehash command is issued. That's by design.

@jlliagre: So,can it be achieved by other means??

Sure, use a different shell that isn't broken by design, like ksh or bash or modify the tcsh code to suit your needs.