Browns, TS uses the volume from entire trades. If you are charting, say, 500V bars and the bar is up to 499, and the next trade is 127 contracts, you will get a 626V bar. They don't split trades.
If you want Easylanguage compatability and EXACT volume bars and don't mind a work in progress, have a look at MultiChats (
Trading and Charting Software for FOREX, Stock, Future and Option Markets) . They are great people behind it. MC has some issues so I'd suggest you read their forum but you can port all your TS stuff over easily, take a 30day free trial and run it off your TradeStation data feed. MC supports about 10 other data feeds.
I use it, eSignal and TS and prefer MC. Still trying to wean myself of the other two.