I finally did THIS!!!.... i really excited, because it was a lot of work... but this worked!!
finally, i installed the plugin touchscreen that i understand is the same that you do Vpeter but this is official...
i do this worked and generate the file pointercal, the plugin saved this file in this path
in this file save the parameters for the touchscreen in this order
Code
xscale --> is the "size" where the touch is moving in the x axe
xymix --> i don't know for what is usefull this value
xoffset --> is when far is the cursor for the touch in the x axe
yxix --> i don't know for what is usefull this value
yscale --> is the "size" where the touch is moving in the y axe
yoffset -->is when far is the cursor for the touch in the y axe
scaler --> is a factor 65536, dont change this value
xt --> resolution x, in my case 848
yt --> resolution y, in my case 480
how tip, in this file the values are factors... for this reason are values with sense. i suggest change for increment o decrement notorius for can you see a tendence and adjust this...