Data sync record column macros

There are cases where we may want to put data from another table into a column when syncing a record. An example would be looking up the id of another record to use in the record being synced. Previously this would mean that all these primary and foreign keys would have to be defined manually. With issue #44 (closed) on the way, we will be able to add records based on non-primary keys and therefore we will need a way of looking up these values to use as foreign key data.

I'm not exactly sure how to define these macros as we don't want to interfer with any possible data being inserted/updated.