Hi

If the child is proven to his father's paternity with official papers and is registered to the name of the father, you have to file an alimony case for child support. The case will be addressed by the committee of the settling family disputes, as of some cases ends on other than reconciliation

The judge will rule a monthly alimony as a penalty from the date of filing the case i.e. from the date of lawsuit
The UAE personal status law stipulates that

Article (78)

1. Alimony of the small child who has no financial resources is on his father until the marriage of the girl or until the boy reaches the age at which his fellow-mates earn their living, unless he is a student continuing his studies with normal success.
2. Alimony of the elder child unable to earn his living, because of a disability or other cause, is on his father should the child have no other funds from which his expenses could be drawn from.
3. Alimony of the female is on her father if she divorced or has become a widow, unless she has funds of her own or has a person in charge of her other than the father.
4. Should the child have no sufficient funds to meet his maintenance expenses, the father is under obligation to complete the required amount within the aforementioned conditions.

Article (86)

1. The alimony of relatives, other than the children shall be due as of the date of the claim in court.
2. The lawsuit claiming a past due alimony for the children from their father shall not be heard if it goes back to a period in excess of one year from the date of submitting the claim to court.