How to run gpg via easypg without adding gpg dir into system Path on windows?

[anhnmncb]

I have an USB which has emacs and GnuPG (both are for windows) so I can
use them portablely.

What I feel not so convenient is that I have to set the GnuPG path into
system %Path%, otherwise easypg will not work. I have tried something
like:

  (setenv "PATH" (concat (concat (getenv "emacs_dir") "/../../GnuPG;" (getenv 
"PATH"))))

in .emacs but without luck.

Any advice will be appreciated.