Implementing TDE for Multiple Databases

I am trying to implement TDE on two separate databases in the same Home on a Windows 2008 server.  I understand that this is possible with 2 wallets in separate directories but I do not understand the proper syntax for the Directory statement in SQLNET.ORA nor how to add the appropriate environment variable.  My 2 wallets would be located in paths similar to these:

d:\pathtowallet\db1\ewallet.p12

d:\pathtowallet\db2\ewallet.p12

If someone could point me to a link that discusses this set-up on a Windows OS or just explain it, that would be great. 

Thanks in advance.