Is there a transformer manufacturer and/or Distributor in the US offering control transformers for pc card mounting, 380 volt primary, and with secondary voltages in the range of 12 to 24 volts, 4 to 10 VA or thereabout.
You may get more people seeing your question in the "Circuit Engineering" or "Electrical / Electronics engineering other topics" forums. This forum is motor control related.
"Venditori de oleum-vipera non vigere excordis populi"
You might try MCI Transformers or maybe Signal transformer. MCI is more likely to have an exact match as they deal in European voltages/frequencies. Just remember that if the tranformer is rated for 50Hz and higher voltages than 380, then the only thing important (other than VA rating) is the ratio of primary to secondary. This would probably give you way more options than trying to find one exclusively for 380. Your ratio is about 15-30 to one so a transformer rated for 480 primary 50/60 Hz will work if the secondary voltage is 16-32VAC. See what I am saying? If you think about it this way you will have many more options, I would guess. I suppose this will be regulated after the transformer so the secondary voltages can have a relatively large range depending on the regulation scheme you have.
This transformer should not cost any more than $2.50US in quantities of 100.
Nbucksa's idea is feasible as well. Probably should be at least considered if this is a production item. Design costs of an "electronic version" would quickly kill any cost benefit for low volumes.