How to use dragging with elements outside the list

[imaxing]

When I use a fixed column as a handle in an elementUI tabel, I can't drag and drop it because the fixed column in the el-table is a separate table, not inside the drag and drop table.

What can I do to make this work?

Example link: https://codesandbox.io/s/nifty-drake-dhhm0?file=/src/App.vue