There was a similar question asked but it wasn't exactly what I am trying to do.
Here is a link to the question: Auto Number Column in SharePoint List with Link to Item
Two solutons were offered to that question.
Could either of these solutions work for an imported list I have where Sharepoint has decided which column links to the item with edit menu? I want to change which column does this as I need to change the format and this means removing the column that has defaulted to being the link to item with edit menu.
Best Answer
You cannot dynamically change the menu column OOTB in SharePoint. To "move" the menu to a different column, you should create a new computed column and wrap the rendering (DisplayPattern) with the _EditMenuTableStart and _EditMenuTableEnd fields.
To see an example of how to do this, take a look at the "AddMenuColumn" PowerShell script from the iLoveSharePoint project on CodePlex. The script is pretty straightforward, so you should be able to translate it into code if you need that (or add declarative using features).
You could also just use the script as it is, to add the new menu column to your list.