We do not have a plugin for MultiCharts but it can be used via the StrategyXtender software. It's supported by a third party provider, Trader Science. They handle this on their own, and any support would need to come from them. The contact is rje@traderscience.com.
The platforms we support with direct sync (plugin) are Tradestation 9.5/10, NinjaTrader 7/8 and MetaTrader 4/5.