Text and Attribute in Line

I'm wanting to change some of the portions of a string of text in a block to be attributes. I have created a dynamic block that has actions & parameters I want, but now I need to change some of the text to be editable. I'm attaching my started block so you can see what I'm working with. The only visibility state that will need these attributes is the "Matchline" state. I've circled the two portions of the string with red ellipses to show which portions which need to be attributes. Please help!

BLOCK.dwg

Trim text object and create new attribute objects where you want the other text.

Could you clarify what you mean when you say, "Trim text object"?

Remove the unwanted text string(s) from the original text object.

Okay, I understand, but what I need is for it to behave like one long text object... like... the block stays centered, regardless of how long the attribute becomes. Also, I can't just center justify the the attribute or text in the instance I did the two separate objects: One would possibly run over the other. And also, I've got a text object, and two proposed attributes to the right of the text object. So they need to look like one long text object.