Merging EHR Data, How to "sign" imported encounters

We are merging data from a different EHR into OEMR7. I have the data from the other ehr that shows when encounter records were signed and who signed them.

How do I add the necessary data to OEMR so that the records show as being signed? I’m good with php and mysql so writing a script to do what needs to be done isn’t a problem if I can find out what needs to be done to the database and which tables so that this information is correct for OEMR.