Am I right in thinking that I need a Certificate of Compliance completed before I give any information on this?

You might want to review 3413:

(i) Disclosure pursuant to issuance of subpena or court order respecting grand jury proceeding
Nothing in this chapter (except sections 3415 and 3420 of this title) shall apply to any subpena or court order issued in connection with proceedings before a grand jury, except that a court shall have authority to order a financial institution, on which a grand jury subpoena for customer records has been served, not to notify the customer of the existence of the subpoena or information that has been furnished to the grand jury, under the circumstances and for the period specified and pursuant to the procedures established in section 3409 of this title.

For those of you wondering, Randy has lifted that wording directly from the statute, including the two spellings of subpoena/subpena. Interesting how two sets of drafters appear to have formed this paragraph. The original law was passed in 1978, and used the "subpena" spelling. Everything starting with "except that a court shall have authority..." was added to the RFPA in 1986, with the "subpoena" spelling.

It would have been unseemly for the 1986 drafters to correct a valid spelling in the original text, but they were determined to use their own preferred spelling in the text they inserted.