Creating a table with Updatable columns and Read-only columns

Here is My requirement, I'm not sure if this is possible. Creating table called master like col1, col2 col3, col4 , col5 Where Col1, col2 are updatable - this can be done easily Col3, col4 are columns in another table but these can be just a read only ?? Is this possible ? this is possible with View but not friendly with share point CRUDCol 5 is a computed column of col 2 and col5 ? if above step can be done then sure this can be done I guess. Please advise if someone has done similar.