Dell laptop with DisplayPort (but NOT mini) to Thunderbolt monitor
According to Apple's spec page, the Thunderbolt Display requires a Thunderbolt-equipped Mac. So, I don't think there is any way to get it to work. Although Thunderbolt allows for video steams and you can connect a DisplayPort monitor to a Thunderbolt port, the reverse is not true.

If you can get your hands on the older Apple Cinema Display with a mini-DisplayPort, that should work with something like this.