Ok,
Go to Configs Tab > Config Change Templates. Select one of the reports there and look at the code. Some of them have actual variables you can use. I use this section to configure my Cisco Devices primarily.
Once you have found a template to use modify the secion below the Configure Terminal line entry for the Cisco command and your variable.
There are also some on Thwack for further referencing. I usually edit my configuration in Notepad++ then cut and paste in.
Hope this points you in the right direction. goodzhere is very proficient at doing this and may have a How-To guide.