joint trading account investment tracking

My accounting and investment-tracking needs require a custom solution that will allow me to easily monitor and verify activity with joint trading account investments. At this point, I am focusing specifically on Mutual Funds, so the solution needs to be tailored to this type of financial record. As of now, I am unsure if I need detailed analytics, but I do not need features to track trends or manage alerts. This listing is therefore to gauge the cost of building a customized software solution that meets exact needs, without excess features.