Understanding how to update multiple records in serverconnect

I’m trying to do some data conversions as I’m merging two databases. What I’d like to do is create several serverconnect files which go through each record in a table, I’d like to be able to use the values in the record to update a value if certain conditions exist. The conditions could involve doing another database search on another table looking for certain values in other fields. It seems that server connect could do this but I just don’t know the syntax. Any more documentation on database multiple update?

Thanks,
Rick