Call AC Support and have them "Properly" walk you thru the export... BUT if you already have est patients in AC I believe it is too late. The Idea with the AC Import of old demograpics was to quickly and easily populate a fresh clean NEW AC with all of your patients basics and to save you the double entry hassle. But once you have hundreds of your patients in there already, it maybe near impossible to go back in time and do it now....
And again that is why I strongly suggest calling Guardian Angel Support, and letting them get you thru this and let you know what can or can not be done for you and your particulars.... Good Luck...
Paul
