If you are talking about a real slow string-type pad, the program is called "Shine On" (figures dosen't it?). However, you may want to play around with a patch called "Darkside" which comes on one of the (many) disks and is not usually loaded into a stock K25. "Darkside" uses VCS samples and really shows off the k25s' architecture as well as utilizing many of the realtime controlers. There is also a sequence on the same disk (it too is titled "Darkside") where movement of the controls are recorded into the sequence. If you should happen to listen to this sequence please remember that it is recorded on one track and uses only one program which is 24 layer deep.
This topic brings up a point thats' usually not discussed when speaking about K25s. In addition to everything else, the k25 makes for a great VA. Please understand, the K25 is a complex beast. While you may be very happy at the time of your purchase, several years afterward you'll be overjoyed. I have never regreted taking the plunge. I only hope my wife remembers to bury it with me.