mkdir -p custom/ap2
cp -fp configure/ap2/configure.php56 custom/ap2/configure.php56
Add your --with-module line to the end of the custom/ap2/configure.php56 file, and make sure the \ character exists at the end of all lines except the last one. The \ character tells the line configure line to loop to the next line, making the configure settings easier to read. Without the \ character to trigger the wrap, the next line becomes a separate command, which is not correct. (see error below). Once set, type:
./build php n
change configure.php5 to configure.php4 if you're using php4.
If you're using suphp, the paths would be configure/suphp/configure.php5 and custom/suphp/configure.php5.
/sbin/service httpd restart
Please keep in mind that any changes to your stock DirectAdmin setup are beyond our technical support, and you do so at your own risk.
A common error people run into looks like this:
/usr/local/directadmin/custombuild/custom/ap2/configure.php56: line 32: --with-module: command not found
which simply means that the \ character was not correctly added on the line before --with-module.