How to expand a flatten area?

Guys, I need a little help...figured this group of expertswould know this...Im using Richard Goldsteins excellent Spotted Bear MontanaUS Forest Service field and have installed it like this:[Area.185]Title=Spotted Bear USFSActive=TRUERequired=FALSELayer=185Local=scenerySpotted_Bear_USFSRequired=FALSEFlatten.0=3677,N47 59,W113 34.3,N47 59,W113 33.8,N47 56,W113 32.1,N47 56,W113 33Which is how the readme says to do it. Works fine. Only problemis that I would like to extend the flatten area longer along thelength of the run way (8U4 is the field) because theres a riverbeside the field that has a hump in it at the south end of theairfield. How can I expand this flatten area on the North/SouthAxis?Im not looking to create scenery, just modify that flatten area.Are there any wysiwyg design tools out there for this kinda thing?ThanksEric