Add text to the end of parameters (after filtering)

I’m trying to add text to the end of the Mark values on certain Floor elements. I have added the desired suffix to the list of strings, but I am unsure how to add these to the correct items in the original list from the “Element.GetParameterValueByName” node. The list in the “+” node starts at 0, while the first item I want to modify is item #4 in the original list of elements. How do I append the suffixes in the “+” node to only those items with the prefix “UNIT” in the “Element.GetParameterValueByName” node?

@Redrunner262 Try this

change?original+" LOT":original;

That looks like it works, I will try it. Since I am an amateur with Dynamo, is there a way to use this via typical nodes from the library rather than using a Code Block? This custom-code-block method is a few steps ahead of my Dynamo proficiency and I’d like to learn to be self-sufficient, not asking the forum for custom Code Blocks for each of my graphs. Nonetheless, thank you for the response!

I don’t understand your graph. Mine is not working as your image shows. Why is my ReplaceByCondition node not resulting in the items starting with “UNIT”?
Also I would appreciate you showing more of the start of your graph. I’m not sure what comes before the List.Flatten node in your graph. That may be why my graph is acting differently than yours.

Look at the proposed solution carefully.
You don’t need to use the FilterByBoolMask node.

That makes sense. Thank you for elaborating.