How to protect a Custom Client Field?

[Remitur]

Client Fields may be protected, in order to allow the client to insert them when registering, but further only see them in client area, without any way to modify them.

But this seems not to be possible for Custom Client Fields: 

• if you select "admin only", the user doesn't see them, nor can insert them at registering
• otherwise, the use can insert them at registering, but is always free to freely modify them 

I would like to set up a custom field which:

• the user may specify when registering
• he can see in client area
• but he can't modify it

Is it anyway possible?

[brian!]

you could edit the template and make specific, or all, custom client fields read only...

you could also do it as a hook (ClientAreaPageProfile) by looping through the $customfields array and making the same change - though using PHP rather than Smarty, e.g str_replace.