You can create a SQL Server linked server with a custom name by specifying a data source other than "SQL Server" along with the desired SQL Server OLE DB Provider. Below is a T-SQL example that uses the latest Microsoft OLE DB Driver for SQL Server (MSOLEDBSQL) installed from here. You'll also need to set the desired security context and options as you would normally.
EXEC master.dbo.sp_addlinkedserver
@server = N'<custom-name-here>'
, @srvproduct=N''
, @provider=N'MSOLEDBSQL'
, @datasrc=N'<remote-ip-or-hostname>';