nnml-active-file customization

[romeomedina@libero.it]

Hi.

I put in my ~/.emacs the following:

(setq my-nnml-directory "/path/to/my/nnml/directory/")

, and in my ~/.gnus.el the following
(see thread 'nnml-direcory customiztion' on the present newsgroup):

(setq gnus-select-method
       `(nnml ""
         (nnml-directory ,my-nnml-directory)))

, and it worked fine. Now, if I implement the gnus-select-method
setting this way:

(setq gnus-select-method
      `(nnml ""
	     (nnml-directory ,my-nnml-directory)
	     (nnml-active-file "/path/to/my/nnml/directory/bla-bla/active")
))

, everything seems to be all right: I get no error messages.
Instead, if I do:

(setq gnus-select-method
      `(nnml ""
	     (nnml-directory ,my-nnml-directory)
	     (nnml-active-file (concat my-nnml-directory "bla-bla/active"))
))

, when starting gnus I get an error message:

Wrong type argument: stringp, (concat my-nnml-directory
"bla-bla/active")

. I also tried with:

(setq gnus-select-method
      `(nnml ""
	     (nnml-directory ,my-nnml-directory)
	     `(nnml-active-file (concat ,my-nnml-directory "bla-bla/active"))
))

. This way I get no error messages but if I do: 'C-h v nnml-active-file
RET'
I see that the value of 'nnml-active-file' is not what I want,
i.e. "/path/to/my/nnml/directory/bla-bla/active".
Any suggestion about what the right syntax should be in ~/.gnus.el
in order to set 'nnml-active-file' to the desired value using 'concat'?

 
Thanks, 
Rodolfo