Hmmm ... I´m not sure, I understood, what you really wanted
If you want a running Windooze in a Linux-Window, then vmware is the 1st choice!
You have your OS data in a single file, which you can recover (like mv backup-image vmimage) without stress.
If you only want to run single programs, you should use wine. It emulates a DOS/Wondooze OS.
If you have an NT4/W2k/2003-Server with Terminal Services runnin up, you can use "rdesktop" to connect to the desktop.
(
http://www.rdesktop.org/, rdesktop is an open source client for Windows NT Terminal Server, capable of natively speaking its Remote Desktop Protocol (RDP) in order to present the user's NT desktop. Unlike Citrix ICA, no server extensions are required.).
I think, it comes with Suse.