Hello,
I would recommend you to look at Serial Port ActiveX Control. This product will hopefully be the solution you seek. Please, be informed that Serial Port ActiveX Control is a flexible component to create, open and manage serial ports directly from your application which saves you time by providing a high-quality versatile alternative to complicated WinAPI for serial ports.
To read more about its features, please visit the page:
http://www.eltima.com/products/serial-activex/
To download free trial version and test its functonality yourself, please follow the link: http://www.eltima.com/download/serial-activex/
If this product is what you actually needed, please refer to the User Manual for Serial Port ActiveX Control which goes along with trial version download.