setting dynamic field control in bopf

I want to control some fields whether editable or not by setting dynamic field control.

my solution as below:

1. check the field whether editable or not on some logical process and return checked result.

2. set the field control value of field(e.g. glaccount -> f_glaccount) by checked result.

3. implement the code at get_entity, get_entityset, execute_action, changeset_process method.

so, I have to implement the code at 4 methods. I think it's not good solution although it work.

anybody can help me to give a better solution.

thank you very much.