leveling x axis table top

Hi all,
I am looking at the g-code examples but I need some guidance here. The top of my mill table is not level so I need to run a 3/4" router bit(the largest I have) from the max of 14 to the min of -14. Is there a way to write a simple g code routine to cover the entire table where the x axis is -14 to 14 and the y axis is -13 to 13 ? The table is off by about .006 across the entire surface and we all know that just won't fly when trying to make quality pieces. I have read the g-code manuals but the linear motion is only briefly mentioned as G10( axis). I am looking to run back and forth on the y-axis across the width of the table( y) from one end of the length (x) to the other, which should rectify the non-level issue.

Thanks for any help in advance.
Joel

Thanks BigJohn I found some tools to help with facing on the Wiki site.

Joel.