Creating More Than 4 Partitions, Unallocated, Format And Assign A Drive Letter

Two of us have been searching for hours (forums, newsgroups, google) on how to create more then 4 partitions in on the same drive in Vista. We understand you can't have any more then 4 primary partitions. Here is how the Dell M1530 XPS came preconfigured as:

Partition 1 = OEM (Dell Utilities)
Partition 2 = Primiary (Dell Recovery)
Partition 3 = Primary (C Drive with Vista)
Partition 0 = Extended
Partition 4 = Logical

NOTE: Partition 0 or 4 is for Dell Media Direct. The volumes are:

Volume 0 E DVD-ROM
Volume 1 D Recovery
Volume C OS

Partition 3 is 220GB in size. I want to shrink it to 60GB's. This would leave about 160GB as Unallocated that I want to format and assign a drive letter to (a Volume I guess). We've also played around with DiskPart a lot, so we're pretty familiar with it, although not experts. All of the instructions on the web are the same, as none of them work with more then 4 partitions of any type.