Unfortunately, that integrated video chipset does not support dual monitors. If you use a splitter with your current setup, it will only mirror the output. Keep in mind though, you don't need two ports on a video card in order for it to support two monitors... it just needs to support dual monitors.
If you are on a budget, the card you need is here:
http://accessories.us.dell.com/sna/p...9&sku=A1632234
It's $49.00 and it will fit perfectly in your slim chassis. It's one of the video cards dell sells as an upgrade specifically for your inspiron desktop 530s.
I work for Dell tech support, and I'm DCSE certified in just about every Dell product. Everything from printers to poweredge servers. If you have any questions, hit me up.