How to mesh a board with regions of pressure not covering the whole board surface?

This is my .cae file containing a board that has regions of distributed force (ie. pressure) on them. However, when I try to mesh them, my board was highlighted orange. Could you show me a way to mesh this part?

this file, thank you very much!

Also, I was thinking of finding a way to apply boundary conditions to restrict the movement of the board in the negative z direction, but allowing it to move toward the positive z direction (because in real life, the board is rested on a pair of stoppers)