Add drillDown icon with it's functionalities inside node SubProcess collapsed

Hello everyone I have the following scenario :
I want to add the drillDown icon inside the node at the position of the plus icon, I want to replace the plus icon with the drillDown icon. And also have it function as it should.

You can easily reposition the drilldown overlay. However, positioning it on top of the plus icon removes the semantics of the collapsed sub-process.