Achive Goal Seek capablity in Oracle Planning - Financials Module

We have a situation where client wants to use goal seek capability for their forecasting process, however we can not use Start modelling goal seek function beacuse of project constraints. is there a goal seek capability in financials module that we can leverage? Or has any one created goal seek functanality in oot of the box modules, if yes, can you share a overview of how was that achived?