In FileMaker, this would be a field of type Container and you can certainly add one to your table in the starter solution. Whether you are using Filemaker 12 or an older version will be a key detail in your options for working with container fields as FileMaker 12 adds a lot of new container field features.
How you get the right scanned image into the container field of the right record may be a bit of a challenge. I suspect that there are plugins that can aid in this.
On the other hand we do something similar here with digital cameras that use "eyeFi" SD cards. They automatically download via Wireless network to a shared directory on our network. I then have a script that uses Import Records | Folder to import the images into a table of Image records. The user can then pull up a portal of thumbnail images and click a button to link a particular image to a specific "receipt". In our case, we are photographing customer's and their non-ferrous metal that they are selling to us in order to comply with state anti-metal theft law, but the idea of importing images from a designated folder might be useful in your situation.
I saw the manage container, how do I add a container?
Containers are fields.
Open Manage | Database | fields
Select the table in the drop down for the table where you want to add this field.
Enter a name for the new field, select "container" as the field's data type.
Got it working now, thanks.