Sequence of customer exit variables

Hi all,

     How to process customer exit variables in a required sequence? For example, there are two customer exit variables associated to corresponding info objects which are used in the filter section of the query designer. Lets say Variable V1 and V2. I would like to process V2 first then after that V1 i.e., based on the value populated in v2, i would like to populate value in V1 in the user exit level.

    Is there any setting to configure so that i can tell to the system that it has to process always V2 first.

Thanks,

Sheshikanth