Hi Waldo,
You have to enhance event 351 to cater your requirement.
Through this event you can revise the dunning activities defined in Customizing for the dunning procedure (Customizing table TFK047M) during the dunning activity run.
In addition to the dunning activities selected by dunning procedure, dunning level, amount limit, currency, and creditworthiness, the data of the dunning header (I_FKKMAKO) is also transferred.
Based on the information in the FKKMAKO structure, you can put in your conditions to execute the activity for various levels.
Hope it helps...
Thanks,
Amlan