sql - Create writeable multi table select query in Access -

i have 2 tables below schema

table 1 -

id, serial code,  hours    xxxx-aa, 1 xxxx-bb, 2 yyyy-aa, 1 

table 2 -

stage , description  aa, foo bb, bar 

right joins this.

select x.*, y.description table1 x left join      table2 y      on mid(serial, 6, 2) = y.stage 

this gave me desire result. however, readable only. know can create writeable query if separate out foreign key in table 1 joining condition is

select x.*, y.description table1 x left join      table2 y      on x.stage = y.stage 

but there better way create writeable query without .. un-normalize.. table 1?

thanks.

one approach create calculated column called [stage] in table 1 , define mid(serial,6,2). fill table, column automatically populated , allows query if "un-normalized" table 1.