This question is frequently asked in the e-letters we receive about Fichier Origine. There is no unique nor free solution. If there was a publication, try to get or check a copy, or at least the page about this migrant. Internet pages are often not complete. If a source ahs more data, it has usually less details for each raw data, so the closer you are of the searcher, more odds you have to see a copy of the record.
Some publications has a copy of the record.
So, check the source. Go to a library that receives the said periodical or holds the said book. Elsewhere, check the nearby genealogical society. Don't expect someone else to do the job for you. Mormons have over 2 millions of microfilm reels.