Programming :: Communicating From Subshell To Parent Shell

I am stuck at a issue in shell scripting. I had tried all the possible ways, yet unable to reach a solutions. I am working on a application, which runs on C shell. For this I had created a installation script, which installs my application in the system, it is working fine. Now, the problematic part is that I had set an alias in ".cshrc" file, which invokes my application when any user types it. But for an alias to take effect, I need to re-login into the system, because I have to read ".cshrc" file again, in order to take effect of my alias. However I can use "source ~/.cshrc" file after my installation, so that my aliasing works without logging back again. But Requirement is that, just after installing the application, alias should be available to user, without logging back again and without issuing any extra command.

I had tried one other way is that, I had created a symbolic link in ~/bin directory, which points to my application to be run, but even that require, to issue rehash command in order to modify internal command hash table. So, my overall problem is that changing alias in subshell should be reflected to parent shell,without running any other command (all commands should be run in installation script only). Or, in other way how to rehash parent shell from subshell. The ultimate requirement is that,the command that will run my application, should be available just after executing the installation script, either by aliasing or by rehashing, or by any other means.