The government of the Netherlands provides a site that tells that you should be able to extend your visa:
Can I extend a Schengen visa in the Netherlands?
You can only extend a Schengen visa under special circumstances, for example if you are seriously ill. You will need to meet certain conditions. For example, your total stay must not exceed 90 days, and you will need to have enough money to support yourself.
Conditions for extending a Schengen visa
If you want to extend a Schengen visa, you must meet the following conditions:
- Your stay must not exceed 90 days in total.
- You must explain why you want to extend your stay and present documents on request showing that you cannot return to your country of origin before your visa period ends.
- You must have enough money to support yourself as long as you remain in the Netherlands (at least €34 a day); or you must have someone in the Netherlands who can sponsor you.
- You must remain covered by healthcare and/or travel insurance.
- Your passport must be valid for at least a further six months and must not have been issued more than ten years ago.
- There must be no indications that you have other reasons for extending your visa, such as the intention to settle illegally in the Netherlands.
So as long as you can prove to their satisfaction that you absolutely cannot leave the Schengen area until the meetings are completed you may be granted an extension. Normally though it's reserved for the "Force Majeure" circumstances such as you're in a hospital.