Remap Mouse Buttons with Xmodmap

Hi Guys

I am having an issue with remapping a mouse i have a thumb button that i want to remap to be middle click
i used xev to find out that it is button 10 and and that middle click is button 6 and so i tired this but it did not work

  
xmodmap -e "pointer = 1 2 3 4 5 6 10  7 8 9 6 "   

any help would be great

In what way did it "not work"? Did it do anything?

it did nothing, but if i do this

pointer = 1 10 3 4 5 6 7 8 9 2 11 12

it makes button 10 middle mouse, but it does mean the middle mouse button does not work. is there is a way to get both working as middle click