The simple answer ys yes, however you are conducting so many data field transfers it is going to take some major re-programming.
It would be simpler to ensure that there are no Null values in the table.
ie ensure the default for Numeric fields is Zero and for Text fields something like "-", thst would only leave date fields to contend with.
Currently you need to add an "is Null" test to every field, this could incorporate the NZ function as well, in fact you could create a query with the NZ functions in and use that as the recordset.
The standard test looks like this
If not is null(rst!Reference) then ref = rst!Reference

You could also give the object field a value like this
If not is null(rst!Reference) then
ref = rst!Reference
else
ref = "0"' or something meaningful
end if