Hi,
can you please provide more context? What do you want to achieve? Is there a going to be a custom type of task which will have this icon?
As for formatting your SVG path to the required format you’d have to at least replace the initial move command m 256, 512 to m {mx}, {my}. Otherwise the path would always be rendered at the same position.
As for bootstrapping the application with your custom path map please take a look at this example which bootstraps bpmn-js with custom modules.