[TxMt] Inserting a special char at beginning and end of multiple lines?

I have 20,000+ lines that I need to select-all and then be able to insert a special character like ^ not normally found within the document, at the beginning of every line, to allow me to then use Find and Replace to insert a common string at the beginning of each line.

After doing this, I also need to be able to do the same thing at the END of each line of text and run find and replace with a different string on all 20,000 lines.

I know how to use Find & Replace.

What I don't know and what I can't locate in the manual document is how to select all 20,000 lines and insert a character at the beginning and end of each of those lines.

What is the most efficient way of doing this?

Thanks in advance for any help!