1. Uninstalled active perl 5.6.1 and strawberry perl 5.8.9 + reboot
2. Installed strawberry perl 5.8.9,
3. Removed the strawberry related folders from system PATH variable. (I have admin access but I just want to run strawberry for my login account )
4. Installed active perl 5.6.1 + reboot
5. created a new type using 'ftype strawberryperl="C:\strawberry\perl\bin\perl.exe" "%1" %*' , (ftype perl stayed like perl="C:\APPS\actperl\bin\perl.exe" "%1" %*)
6. wrote a batch script like a) add strawberry perl related folders to the beginning of path variable b) assoc .pl=strawberryperl c) execute the scripts(/tests) d) assoc .pl=perl
7. Execute the batch script, my goal achieved, the scripts are compatible with strawberry perl 5.8.9. without disturbing the other users environment which were using active perl 5.6.1.

I dont think that is an efficient way to achieve the goal, but it solved the purpose. If there is an efficient way than the one I mentioned about, please let me know.

Actually the main Idea behind installing strawberry perl was to make sure that the old scripts that I have which worked well with active perl 5.6.1 is compatible with newer strawberry perl. But one unfortunate/fortunate thing is the support for pseudo hashes has been removed from perl 5.10, so installing strawberry perl 5.12 didn't suit well for my scripts(fields module can be used, but that is a different story, as I was only asked to check compatibility). So I finally installed strawberry perl 5.8.9 and everything seems to be working fine. Thanks