Insert text at the begining of files with rename operation

I have a folder of file names that start with an ascending number (100, 101, 102 etc) with a tile that follows. I'm trying to insert text in front of the ascending number. I tried a find an replace by keeping the first number ( 1 ) but then when it got to 110 or 101 it would replace it twice. Not what I was looking for. I've tried some wildcards and have been looking around for an example but I can't seem to find anything. I could be doing this wrong, any advice?

One way to insert text at the start of each file name: