takumiirie

# set "Apply to range" to whereever you want to apply setting.

# set "Format cells if..." to "Custom formula is" and paste following code
# Following Forumula will detect if it's match with regex or not.
=REGEXMATCH(INDIRECT("R[0]C[0]", false),"<PUT YOUR REGEX HERE>") = true

# set your "formatting style"

That's it!