To stop Explorer raising errors when you try to access the network share or when you try to start Explorer using different credentials, you have to do some command link magic first.
Open a new command shell and run this command if the share is accessibly using only your admin credentials:
net use \SERVERShare * /USER:DOMadmin_user
Type the password at the prompt:
You should see output indicating success:
The command completed successfully.
Now when you try to access SERVERShare in Explorer, it should just work!