Agreed Upon Procedures
Often times an audit, review, or compilation may not address the specific concerns or areas that you want to focus on.
In this situation an agreed upon procedure engagement may make sense. It allows you, the end users, to decide on the procedures that should be performed and to what extent.
These engagements can cost much less than an audit and while the issued accountants report does not express an opinion, it does provide a detailed description of the procedures performed and the related findings.