font lock regexp match question?

[Z]

Hi,

I tried to write a new mode, but don't know how to font lock regexp
subexp match (I know how to font lock full match).

E.g. I want to font lock all "c" after "p".

And I write:
(setq wf-font-lock-defaults
      '(("p\\(c\\)" 1 font-lock-function-name-face)))

and in major mode,
(setq font-lock-defaults '(wf-font-lock-defaults))

But it didn't work, any suggestion?

Thanks,
Z