Unfortunately there's no way to recover qvd creation script from qvd. Best practice is to perform a backup activity once in a while to avoid such scenarios.
The qvd doesn't store the script which has created it. You may open the qvd with an editor like Notepad++ and maybe looking to the lineage-part to get a few hints and information (it's for example depending on if lineage was enabled and from which source the data was created) but there won't be a full load-script.
Did you look for any backup-files (regular from the IT, own ones, windows shadow copies or other snapshot tools, ...)?
A QVD is usually created by a statement along the lines of:
Store * From SomeTable into SomeFile.qvd(qvd);
So even if this was saved into the QVD (and I believe it isn't), I doubt it'd help.
If the file creating the QVD was deleted, and you don't have a backup, I'd suggest checking for the reload log from the file in question, as that would have the script in it. If that's gone too, and there are no backups of either, I think you're out of luck.
That's already a good starting point to re-create the qvw and more as the most qvd's contain but it mustn't be the whole truth because there might be multiple other statements within the script which might have an impact, for example:
any pre-loads to create exists-filter or to sort field-values
the interpretation-variables at the beginning of the script
Just an addition to the suggestion from @Or. The document-log will contain most of the extra information which I mentioned above. Beside the qvw-application folder the document-log is also stored and backup within the task-area.
