Drive Creation During unattended install W2K3

[Fieldzy]

Is it at all possible to firstly assign the CD drive to say z:\ during the unattended install and then create say a D: and E: formated as NTFS.

At the moment I ran a the following scripts after logon.

Move CD drive:

Diskpart

select volume d

assign letter=z

Create Drives

Diskpart

Select Disk 0

Create partition primary size=15355

assign letter=d

create partition primary

assign letter=e

But it seems not to work everytime.