.ecfg file name

I'm generating some .ecfg files using post build events in my projects. I'm using .NET 4.5 and Visual Studio 2012. My file names are in the following format:
{<guid_id>}_<nameOfClass>.ecfg
But I noticed that most of the other ones are just <nameOfClass>.ecfg

I didn't see anything in ESRIRegasm.exe to name mine <nameOfClass>.ecfg.
How do I do this?