I discussed this question with Fabio Guzman, the attorney who answers questions in the Legal Section. He told me that the courts in the DR recognize a will made in the US if it met the requirements of the jurisdiction in which it was made. He examined a copy of my will, made in the US, and assured me it would be accepted by the courts in the DR.
Some of what he had to say on the subject of wills by expats can be found here
Additional Question on Wills by Foreigners and
Wills for Expatriates
Like you, I own a corporation in the DR and my children are the beneficiaries after my wife. After talking with Fabio, I am not worried.
I recommend that you contact him. His website is
www.drlawyer.com and his email address is
info@drlawyer.com For your peace of mind, you should have him examine your papers to be sure your assets in the Dominican Republic will be distributed as you wish in the event of your death. You may also want to consider engaging him to protect your interests.
If all the attorney you consulted said was "don't worry", you didn't get much for your money. Whether or not he is right isn't the point; a client deserves more of an explanation than that to avoid worrying.