Think of the code like this (quick and dirty):
ChannelIndex = 0
FOR ListOfChannels
FOR 1...100
QueryListOfChannels += ListOfChannels[ChannelIndex++]
DONE
responseData = QueryTwitch(QueryListOfChannels)
UpdateWebPage(responseData)
DELETE QueryListOfChannels
DONE
There are probably better ways to accomplish this, this is just off the top of my head.