Specifing Folders for Secret and Public Key

[=k3Rn=]

Hello!

I am running GnuPG on Windows XP using Thunderbird and Enigmail.

I want to tell GnuPG where it should search my secret-keyring and where
to search my public keyring.
I am thinking about having my secret-keyring on an usb-stick mounted on
let's say y:\, and my public keyring should be stored on my hard disk.

I think you can imagine what i wanna do. I just want to know a clean way
to do this. Just changing GnuPG's homedir isn't all i want - as far as i
understood it.

Thanks for any hints concerning this problem!

Greets,
=k3Rn=