The OpenStudio CLI/SDK does support the CoilSystemCoolingWaterHeatExchangerAssisted object. Indeed, it doesn't look like the OpenStudio Application supports it - yet? You're left with 2 options IMO in the short term:

• develop an API script and/or measure (Ruby, Python, etc.), similar to this .rb file
• hack your .osm file so it reflects the required components in this corresponding .osm file