You're talking about two different things. XMLA is not an alternative to SQL, you use it to (amongst other things) process cubes. If you want to dynamically process fact dimensions based on your variable then you have to use it to some degree. You don't have to be an expert; in SSMS you can right click on a cube object to process, set the options and then script it out. You can then examine this script and customise it to your needs.