Go and share the database normally within ACT (tools, Databases maintenance, Share Database) we will change this in a minute.
Then going through the Windows explorer to the the location of the supplemental files folder. Create a windows share manually.
You will need to have installed the ACT7 SQL instance in Mixed mode so you can make the change. Also, you will need SQL management Studio
with SQL management Studio, connect to the ACT7 Instance and look for your database.
There is a table called DBCONFIG
Look in DBCONFIG for a field called DATASTORE
Replace the CONFIGVALUE in DATASTORE to your share name