To configure cpanp to use this, you need

$ cpanp
CPANPLUS::Shell::Default -- CPAN exploration and module installation (
+v0.9011)
*** Please report bugs to <bug-cpanplus@rt.cpan.org>.
*** Using CPANPLUS::Backend v0.9011.  ReadLine support disabled.

*** Type 'p' now to show start up log

Did you know...
    You can update CPANPLUS by running: 's selfupdate'
CPAN Terminal>

CPAN Terminal> s conf buildflags--config installhtmldir=

Key 'buildflags' was set to '--config installhtmldir='
CPAN Terminal> s save

Configuration successfully saved to CPANPLUS::Config::User
    (....cpanplus\lib\CPANPLUS\Config\User.pm)
[download]

Editing .cpanplus\lib\CPANPLUS\Config\User.pm by hand is easier :)