making action buttons to add and subtract cells

Hi, I am new to macros, and have no background in VB, I do have some C+ and pascal skills, so I probably can learn fast.

what I am trying to do is this :
Cell A1 has a number (ex 40)
Cell B1 has a number (ex 32)
Cell C1 has a number (7)
Cell D1 has a number (2)
Cell E1 has a number (9)

I need four buttons :
"button 1" should work only if D1>0 and should subtract 1 from D1 and add E1 to B1 up to the maximum of A1 (if the addition would bring B1 higher then A1 make B1 equal A1)
"button 2" should ask for a number and subtract that number from B1 down to a minimum of half A1 (if the subtraction would bring B1 to lower than A1/2 then make B1 equal A1/2)
"button 3" should ask for a number and add that number to B1 up to the maximum of A1 (if the addition would bring B1 higher then A1 make B1 equal A1)
"button 4" should make D1 equal to C1 and do the same for D2=C2 D3=C3 and so on.

can anyone help me do this ? or show me a guide in which I can learn for myself ?
thanks a lot !

thanks !

I created a module and copied this to it,
but when I create a button it doesnt let me choose the module to attach to the button.
can you help with how to use this ?

thank you both ! that worked
now all I need is the function for recieving a number from the user and using it,
and a function that gives a random number between 1-6