Requisition - items validation and security rules

 Hello,

This is a technical question.  We would like to use the Oracle facilities for validating item on requisition line according to their expense account definition.

We want to restrict user to use only items defined with specific cost center in their default expense account.

As the internal requisition generate distribution combinations with the employee expense account, we cannot restrict anymore items the same way as before;generating combination with items account.

So, we want ot use the package POR_CUSTOM_PKG and use probably FND_FLEX_SERVER to validate each line.

Is FND_FLEX_SERVER the rigt package?

Thnaks!