The simple answer is that you need to enter into a contract with the danish cleaning company which explicitly specifies that that company cannot do business with any entity you disclose to it unless the company pays you the properly proscribed fee (whether this is a fixed fee, a percentage of the contract, or some other definitive sum).
The contract needs to be drafted in a broad enough fashion to ensure that the danish cleaning company cannot, for example, simply have an affiliate do the work to avoid paying you, but it also must be tight enough and contain the "magic" words to ensure it is legally enforceable. There are other factors such as jurisdiction and indemnification provisions in the agreement that you must consider as well.
Performing your due diligence now can ensure that you avoid wasting a lot of time and potential money in the future. You should definitely contact an attorney, and I personally would be happy to assist you in this matter. Please feel free to contact me at 404-518-6668 or at
yasha@heidariplank.com.
DISCLAIMER: Although I am an attorney, absent a signed retention and engagement letter, I am not your attorney. There are no exceptions to this rule. Moreover, you shall not rely on the information I am providing you, as it is only for your general knowledge and educational purposes. Indeed, my analysis is always based on the laws of Georgia, and your jurisdiction might have substantially different laws and requirements. As such, you should always contact an attorney that practices in your local area.