ouch, you would at a minimun change motherboards and processors to get an agp port, can't be added on, only built in.
do you have the make and model number of the machine.
Really don't know what to say.
You may be throwing good money after bad, could be time to upgrade to a newer machine.
If you don't have an agp port you would have to find a pci card.
But with the 200mhz processor it's hard to say what the performance will be like.
I would try this one, but hopefully get it from someplace that will allow you to return if it doesn't work
buy.com link
http://www.us.buy.com/retail/product.asp?sku=10216798
Manufacturers link
http://www.pny.com/home/products/Vcard_MX400PCI.cfm
specifications to be able to use
Minimum System Requirements
Intel Pentium®, AMD-K6 class processor,or higher
One available PCI bus slot
64MB RAM
A CD-ROM drive
10MB available disk space
Windows 95 OSR2, 98, and higher
Windows NT4.0 with Service Pack 5 or 6 Linux OS