Keltner Channels based off an EMA... request some help!

 

I am looking for some help with the code for the Keltner Channels. I figured out how to base it off of an Exp Moving Avg. However, how do I define a specific offset of the upper and lower keltner channel bands from the middle keltner band (Exp Moving Avg)?

Any ideas would be helpful.. thank you!

 

Just add or subtract X*points to the middle band and place the results in two more indicator buffers. However don't Keltner bands have their own price type to input before taking the moving average?