Yes, you can but it's not as you would do it on Novell or Unix. That is you can't just expand it from other volumes.
With NT Diks Administrator you can create what is known as a "Volume Set" this can be a collection of multiple "chunks" of free space from different physical disks.
In order for this to work there must be "FREE SPACE" not unused space in another volume but space that has not been used, formated, partioned or assigned a drive letter. Then all Disk Administrator does is basically join that space to the selected volume, creating a "Volume Set".
Usually though system volumes in NT are not managed using NT Disk Administrator as it is very limiting. Typically you would want to do this at a hardware management level where you can add another disk for example and then expand your volume. Or some other Volume Management software. Thats my experience with it anyway. Hope it helps. Good luck.
Use Software like Server Magic 3.0 to resize your partitions. I do not recommend NT Disk Administrator except if you are not 100% sure what are you doing.