Declaring certain blocks of text as string?

Ok I hope this doesn't sound too confusing. I am building a little macro recorder, and in my application it has a textbox which is used as a mini-script editor.

In this script editor(textbox) my users can use different tags, something like this, each set of tags has their own function. Example- <Lk>The quick brown fox</Lk> The users will most likely enter multiples of the same codetags in the same textbox, hence why I need different IDs for certain blocks of code.

Now my question is how could I have my users kind of give the tagged block of code an id or name so it can be used in another part of the program?

so basically I have a block of text between tags in my textbox declared as a string, instead of a whole textbox declared as a string. My program will use the variable(the name of the block) in other parts of my program, but a quick example is

messagebox.show("Error With" & CodeName)

So a msgbox pops up with the string between the tags

If you need any more information feel free to ask. I hope this wasnt too confusing lol.

I already have code that removes the tags and gives me the string between(Thanks Paul), I just need to know how to have my users give the blocks of code a dynamic name which can be called from other parts of my program.