Conditionally Format Partial Text

Hi,

I have a workbook that is like an internal search engine.

I would enter what I'm searching for in $A$1 and then a list appears in range $A$3 to $A$20.

The list actually appears while I'm typing and shows everything that contains the letters I'm typing in. I'd like the cells to highlight the font when it's matching what I'm typing.

I've completed a mock-up of how I would like it to look. Hopefully a simple conditional format using a formula will work, I'd rather not have to use a macro.