I suggest replace the keyboard

Hello,
Change the key pad,

http://www.insidemylaptop.com/disassemble-hp-pavilion-dm3-series-notebook/

http://www.machinaelectronics.com/store/library/article.cfm?f=key_type_k02

http://www.insidemylaptop.com/replace-damaged-keyboard-hp-pavilion-tx1000-notebook/

Hope this helps