Security locks on tables

Hi,

My customer wants to have a lock on certain tables preventing some users to change the data.

Say you have an item in InventTable with form EcoResProductDetailsExtended.

Some Items will be locked for a normal user (a role will be able to set item locks on the item)

and when you shift to the next item this might be open for change.

Some additional tables will not be allowed to update/change for this "locked" item like

EcoResDistinctProductVariant, EcoResProduct, InventItemBarcode, InventTable,

UnitOfMeasureConversion etc. (all controlled by a separate table with lockYesNo, itemid, table).

Then there will be another role allowing a user connected to this role to change the tables anyhow.

What is the best way of achieving this?

I am running MS 2012.

/Fredrik.