Is it possible to use a ConnectionCallback without an External Script?

I would like to enable a callback function for a port connection change, in a block within a blockset I am developing for several users. But I do not want to require each of these users to maintain any m-script files in order to use these blocks. I have attempted to use an anonymous function or a function handle within the model's workspace, but I haven't found any syntax which has worked. The functionality I want for this callback would be the same as the block's CopyFcn callback, so the function could be something as simple as:

@(x) eval(get_param(get_param(x,'Parent'),'CopyFcn'))

'x' would be the connection port's handle, its 'Parent' would be the block, and so this line would evaluate the block's copy function. But how do I get the port's ConnectionCallback to execute this line without using an external script?