If you’re using Notepad++ (and I highly recommend it as a free and powerful text editor), you will first need to install a plugin.
Adding the Language Help plugin
To do this, from Notepad++ select Plugins→Plugin Manager→Show Plugin Manager . If you do not have the Plugin Manager, please refer to the Notepad++ documentation for instructions on how to install it.
Once you have the Plugin Manager displayed, scroll through the list of plugins on the Available tab and find the “Language Help” entry. Tick the box to the left of the entry and then click the Install button. This should download and install the plugin. Step through the install process and follow the prompts. You will likely need to provide Administrator credentials and Notepad++ will likely need to restart.
Adding a new Language Help configuration
Once Notepad++ has restarted, you should now see an entry on the Plugins menu for Language Help. Walk right on that and select Options.
Next, click on the Add button in the top-right. This will allow us to add a new Help entry. You can set-up multiple help entries and associate different help files and actions with different languages/files. For example, for 12d Programming Language (12dPL) files (.4dm) you could open the 12dPL help file and for Modification & Template Files (.mtf) you could open the 12d Model help.
Type in the Name– this is simply a shorthand label for this particular help file configuration. Specify the Extension/file mask to use to associate files with this configuration. The Extended help file path field is where you can specify the path to the PDF help file. If you want, you can simply browse for the PDF help file or paste the path into this field. However, we’ll be doing some more advanced configuration so we can search the PDF for the keyword selected in Notepad++.