Warning - CIMA do change the exemption rules from time to time so always make sure that you check the situation directly with them before beginning any study programme.
You should ensure that you have read the current CIMA exemption policy to ensure that you comply with the processes and avoid delays http://www.cimaglobal.com/Starting-CIMA/Starting-CIMA/Exemptions/
Successful completion of AAT Level 4 will currently exempt you from the CIMA Certificate in Business Accounting. You will be able to begin your studies at the Professional Qualification stage.
Various degrees and other qualifications may also qualify you for exemptions, for the most up to date list use the exemptions search http://www.cimaglobal.com/Starting-CIMA/Starting-CIMA/Exemptions/Exemption-Search/