Supporting Windows

Hi all,
I have created win PE CD and customised it to run one of user application through it. I am able to acheive this successfully.
Can anyone let me know is this drive name from PE i.e. X: can be changed? How to map local computer drive's with others in PE CD(as shown in below table).
Also inform me is it possible to run any package/installer through PE CD.
In the current PE CD Creation steps,We are creating a Virtual Drive (X:) but this X: Drive is already present in one of my Machine, so in this condition we have we have to perform mapping of drives with the actual Drives Present in the System and Drives Displayed while PE Execution. This mapping may be as shown below:

Hard Disk Drives: ----> mapped to Windows PE drives
C:----> C:
D:---->D:
E:---->E:
F:---->F:
G:---->G:
H:---->H:
I:---->I:
S:---->J:
V:---->K:
X:---->E:
Requesting you to get back on this at the earliest. Thanks in advance.
Thanks and Regards,
Abhijit