Pre-populating Custom Fields on a template

Hi everyone, We have templates that are created through the Web UI with Custom Field fields on the template. The package is being created based off the template, and certain information about the signer needs to be prepopulated on the form (i.e. Name, DOB, Address, etc.) Is it possible to inject data into the custom fields so that when the end user goes to sign the form those fields already have the data populated? Thanks in advance for any help or insight on this issue!