Hi,
the problem with Eagle is the fact, that it won't allow to create SMD pads other than rectangular.
In that particular case you would have to use five SMD pads, one 2.4X1.65mm, and four pieces of 0.75X0.23mm, placing them according to the datasheet outline. I'd call them TP1 through 5.
The symbol must contain those 5 pins as well to create a proper device. I suggest to put them underneath the "frame" of the IC-symbol. (pin length - point, visible - off)
The symbol should look about like this: (attachment) Note that one of them is loacated just on top of the regular ground pin. So you just need to extend the net into that pad.
Save the symbol and create a device using that symbol and the package you have already done.
Connect pins and pads as you do with any device.
That method has the advantage, that the solder stop will include the entire thermal pad.
Boncuk