I found this from the Hukoomi (Qatari e-Government) website...Maybe this might help you. I suggest your fiance try calling the phone numbers below so he can ask specific questions and get all the information you need, or at least point you in the right direction. Good luck!

Marriage Solemnisation

The Supreme Judiciary Council oversees marriage solemnisation and registration procedures in Qatar. The solemnisation is carried out by registered Marriage Officers according to the Shari’ah Law.

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The fee for solemnization is QR 300 if the contract is signed in the house of the contractors, and QR 200 if the contract is signed in the house of the official.

For inquiries, please call +974 4452214, +974 4452218 or +974 4452202.