Is it possible to reference an external icon list for Addin toolbar?

In the addin code

cmdGroup.LargeIconList = iBmp.CreateFileFromResourceBitmap("MachineryMacros.ToolbarLarge.bmp", thisAssembly)

Be default, the icons .bmp file is stored in the project and compiled into the .dll.   Is it possible to reference a external bitmap, one thats stored in the same folder as the addins .dll file?  

SolidworksApi macros