Total Area Field in MText of multiple PLine (addition and subtraction)

Hi,

I am new in Lisp and in need of a lisp to total multiple close plines with addition and substraction of plines.

Just as in the build-in Area command, I can Add then Subtract but I need the result to be MText as Field onto the drawing. When any plines changes, this area field changes as it should be. Not sure this can be done for multiple plines and calculated values.

Eg. Area add 2 plines then subtract 5 other plines and have the net area (sq.M) in MText as a Field. Or even just addition of 2 plines.

The units I am using is metric (sq.M) and MText on layer 18-TEXT with text height 180.

Thanks in advance.

mcmk8

Lee Mac has a nice routine for total area of a group of polylines at: http://www.lee-mac.com/areastofield.html