I don't know what partition manager SuSE's installation CD uses, but you can use Knoppix's LiveCD and the 'qparted' application to resize the windows partition.
Take a look here: http://www.linuxquestions.org/questi...42#post1063642
He did what you want to do, but notes that the partitioner that comes on SuSE's CD cannot handle NTFS (which is what you probably have). So, I suggest you:
(1) download/burn Knoppix onto CD. You can get this from http://www.knoppix.com/
(2) shutdown most programs within windows, then defrag the entire partition.
(3) boot up with Knoppix, run qparted, and resize the NTFS partition to the size you want
(4) reboot the computer, boot up with SuSE's install CD, install on the new blank partition you created using qparted.
(5) I don't know if SuSE will automatically add windows as an entry. If it doesn't, follow the advice given here: http://www.experts-exchange.com/Oper..._21087521.html
. You may have to change '(hd1,1)' to wherever windows is currently installed.
This procedure should work for you. It seems that you have never installed linux before so I STRONGLY suggest backing up all important data (programs can always be reinstalled). Then, you are free to tinker around with this. It will take some time, but it's worth it.
If you have any more questions, just post them here.