Adding Parts of a Name to a Batch of Files

Hello All,
I am VERY new to Dynamo and I am trying to use Dynamo to rename a each file in a large folder of files. I want to add “_R22” to the end of the current file name to show that all of the files were created using Revit 2022. My problem is that I have figured out how the “find & replace” function works, but I can’t seem to find anything that will add script after the filename. All of my files have different names for different families, and I cannot just batch replace text that is not there. So for example say I have 3 files named “DOORJAM”, “BRACKET”, and “BENTPLATE” and I want to rename them so they all have “_R22” after the filename. I don’t want to replace any of the text in the current name. So I would like them to read as “DOORJAM_R22”, “BRACKET_R22”, and “BENTPLATE_R22”. Is there a command or add-on that I need to install to get this?

You can combine strings just by adding them together:
myString + "_R22";
If you plugged your list of file names into the myString variable, it would append the "_R22" suffix to each one.