Expression Help - Font style rules

Hello!

I have created a 'master page' to control the text on my other comps using an expression

comp("01 MASTER").layer("1 TX INFO").text.sourceText

TX info is something like: Tomorrow 9pm.

is it possible to add a rule? if say 'Brand New' was added to the TX info = 'Brand New Tomorrow 9pm' i would like the Brand New to be in a differnt font style aka 'Brand New Tomorrow 9pm'

Is this possible with expressions?

Thanks for your time