Since http://www.smorgasbordet.com/pellesc/ seems to be offline, you can find the Download of Pelles C here in this Forum.
To add the folder to the Exclusions list, follow these steps: Open the Bitdefender window. Click the Settings button on the upper toolbar. In the Settings Overview window, select Antivirus. In the Antivirus Settings window, select the Exclusions tab. Make sure Exclusions for files is turned on by clicking the switch. Click the Excluded files and folders link. Click the Add button, located at the top of the exclusions table. Click Browse, select the folder that you want to be excluded from scanning and then click OK. Click Add and then click OK to save the changes and close the window.