Actually, I think you do have a floppy controller.  I haven't looked at all the manuals, but the one I did look at shows a diskette interface connector adjacent to the processor.

 

You likely have three choices; temporarily hook up a standard 3.5" floppy drive, try to find a USB external floppy that the computer will recognize as the " a: " drive, or google slipstreaming and learn how to integrate the SATA/RAID drivers onto a Windows XP installation CD.  I've never done the last one, but many folks tell me it isn't as difficult as it sounds.  The only caution is that you need to do it from a computer that uses Windows XP as the operating system.  Other users who have tried it on Vista have stated that the resulting CD could have some flaws.  This may be only a rumor, however, as I've not seen it confirmed.

 

It is possible to build an XP CD with the Intel Matrix Storage controller integrated such that the drives are detected during install and it is well documented on the web. I found however the most useful source was in fact the XP installation disk that came with a system with this hardware config. The system had modified TXTSETUP.SIF and WINNT.SIF files compared to the files on a generic XP disk.