Okay... I have to add something
After reading through the posts, I think that most people do not understand what you are asking for.
I know that Acronis True Image will allow you to mount your backup as a drive and extract information from it, without having to restore the backup and wipe out your other data. I do not know if you can do this with the Windows 7 built-in backup.
Subscribing to Carbonite would also give you what you need. You could make your regular backups, just as usual, in case of a complete system meltdown. You could then rely on Carbonite to keep your data backed up regularly. It isn't entirely intuitive, but it does work well. Type "Carbonite" (without the quote marks) into a search engine to find it.
If you would rather just buy a program, Acronis True Image will allow you to remove data from a backup. You will need to read the instructions to find out how, but it isn't difficult.