Windows 7 How to change show desktop button behavior in windows 7?

hi im using windows 7
i would like to know if it is possible to change the behavior of show desktop button in the lower right from its default winkey+d and change its behavior to be similar to winkey+m

i always use the show desktop button however im using a rocketdock and pressing the show desktop button will also minimize the rocketdock

can its behavior be changed like doing something in the registry?

thanks