Replacement for Truecrypt file container on Bitlocker machine

Dear all

First of all please accept my apologies for my lack of knowledge on the subject but I need your advice. I have been using Truecrypt to secure my private material on a work Windows 7 notebook computer protected by Bitlocker. I have followed the advice on the Truecrypt website:

http://truecrypt.sourceforge.net/

but am unable to encrypt the virtual drive with Bitlocker. I am also not sure I want to use this process as I guess the Bitlocker key will be the same for both my hard drive and the virtual drive. Can anyone recommend any software of similar functionality to Truecrypt for the creation of encrypted file containers?

Thanks

Mike