Regulation (EC) No 1907/2006 of the European Parliament and of the Council of 18 December 2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), establishing a European Chemicals Agency, amending Directive 1999/45/EC and repealing Council Regulation (EEC) No 793/93 and Commission Regulation (EC) No 1488/94 as well as Council Directive 76/769/EEC and Commission Directives 91/155/EEC, 93/67/EEC, 93/105/EC and 2000/21/EC (consolidated version).
For the REACH legislation and its application, you can always contact the Belgian helpdesk REACH (in Dutch or French) of the FPS Economy. For certain topics regarding your obligations under REACH, you can consult the helpdesk of the European Chemicals Agency (ECHA). This also applies for instance to technical support when using IUCLID and REACH-IT.