Here is some code to be used in a custom module in Drupal 7 in order to create a custom link in the admin menu. This item will show up in the Configuration section and it is particularly useful with the administration menu module.
One of my latests tasks was to allow a link that would take a user id and a node id as an argument, and automatically create a new order that would have some fields pre populated and ready for further editing. Scope is to use the user id as the client that does the order and to automatically select the product depending on the taxonomy term of the provided node.
In my case I offer a series of links through a custom view template, that uses data from each row results to built the link.
Here is the code for my module, hopefully it will be useful for someone: