You need to download and load it in your script. After download you have 2 ways to load it:

1) Unzip the "DCentral.zip" copy it into the your mIRC directory and use this command in your mIRC: //load -rs $+($shortfn($mircdir),DCentral\DCentral.mrc)

2) Copy it to directory and on the mIRC Script press Alt+R, click on "File" Menu from its Menubar and click on "Load" find the "DCentral.mrc" and load it.