Bitlocker is pre-boot encryption so you will have to use a pre-boot method of formatting.
This is actually not as easy as you might think because even if you load up the drive with a boot disk, it will not let you format it via normal options.
But to answer your question, yes.
You can actually access command line from the windows pre-boot installation (and repair) screen by going to advanced options.
Once you are in an elevated command prompt, the rest should be pretty straightfoward. You just blow away the partition and build a new one.
EDIT:
Orrrrrr... if you are using this an external, you can connect it via usb (you wont be able to "see" it but its there) and open diskmgmt.msc. Then just blow away everything on the external and reformat.
There is no way to do this and keep your information though, which is the point.