Exposed Pad QFN

Hi

I am drawing a qfn.dra file. The 32 pads are defined with Pin(Top, SolderMask Top, PasteMask Top).

In the datasheet, it is recommended not to solder Exposed Die pad in the center. 

So my question is :is it necessary to define Pin in the same way as i did for the above 32 pads OR can i design it like Pin(Top, SolderMask Top

and do not use PasteMask top as i do not want it to be soldered OR do not define anything for exposed pad at all) on that pad. This is a sensor chip so i would avoid using any copper underneath this sensor.