It should work. You would just have to add the path to the file in the php when you specify the file. Does the attached page work? I'd need to see a copy of the page that doesn't work and I'd need details like what file path you are uploading to in order to give you the exact code to add and what line to edit.
I'm not sure what database or column you are using for the file, but line 120 would look something like:
$Email->addAttachment("../../../../YourUploadFolder". ($RecordsetName->getColumnVal('FileColumn')) ."");