I suppose you deleted the file somewhere on your iPad and would need it again. If this is not the case, please give a more precise information of what happened.
If you backed up your iPad to iCloud, and the file isn't stored in another app, it will be lost. Sorry!
If you back up using iTunes, and the file is in a backup, you could "rescue" it by restoring the iPad and using the backup with the file included to set it up again.
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.