I got my cable from
Hap griffin for my D70 ,
Shoestring Astronomy is another choice . Both are US based i think , unfortunately for your camera it looks like you have to purchase the
remote switch and then send it to them for modification
. But well worth the hassle , its great to have everything automated and sit back and relax....well until the dreaded image processing part
.With your LX200 you should have a rs232 cable that you can use for scope control in unison with a planetarium program , don't forget to plug one end of the cable into the left hand rs232 port on the scope base