Is there anybody who knows if it is possible to use dual boot with Grub (for instance) loading Backtrack and handover to Windows Boot Manager for Bitlocker?

I have a notebook partitioned for Win7 with 100MByte System Volume and 120Gig Boot Volume.
A 3rd primary partition remains for Backtrack Installation.

I would like to have boot loader and boot code for Backtrack in the 100Mbyte Partition in the beginning.
The only problem is that it does work for an unencrypted windows volume but not if it is encrypted.
As usually the Windows Boot Loader would ask you for your encryption key.

Can Grup somehow be modified to hand over to the regular Windows Boot Loader/Manager instead of loading the Windows OS directly?

So in fact I would need to have Stage1 code in MBR on the HDD and two Boot Managers in the first partition.
Where Grub is loaded via MBR code and Grub can hand over to Windows Boot Manager (WBM)?

Best regards,