Thank you. I've missed that part about user variables and assumed "dot" notation was just a way or naming variables and it would do by name substitution. The second part works now.
As for your first question, it's not tivo dvr that sets channel but rather tivo AV device in ISY Portal. Sorry if that wasn't obvious.
But, everything seems to work now. Including skill setting variable. Thank you.
Another annoying thing, Alexa seems to have trouble with word "tivo". Most of the time it says "I couldn't find the skill tiv-O". I've tried "tivo", "teevo" and even tried saying it as "t-ai-vo", just in case. Worked sometimes but not reliable. Works much better as "dvr". Don't think this one is the problem with the skill though.