There are several ways to do this but I think the easiest way to get this in the format you're looking for will be to add additional copies of CONTHIST to your report and filter each one on a specific date instead of filtering one copy of CONTHIST on multiple dates. To do this, follow these steps:
1. In the Database Expert, add CONTHIST to the report again. When you try to add a table that's already in the report, Crystal will notify you that it's there and will ask if you want to alias it. Then it will add the table with a suffix of "_1" on the table name. So you'll see CONTHIST_1 in your list of selected tables.
2. Add CONTHIST again to get CONTHIST_2.
3. Link to these two tables like you're linking to CONTHIST.
4. Modify your selection critera to something like the following:
{CONTHIST.ONDATE} = Date (2010, 04, 13) and
{CONTHIST.REF} startswith "Name of our event" and
{CONTHIST_1.ONDATE} = Date (2011, 04, 11) and
{CONTHIST_1.REF} startswith "Name of our event" and
{CONTHIST_2.ONDATE} = Date (2012, 04, 17) and
{CONTHIST_2.REF} startswith "Name of our event"
5. Modify your report to us the RESULTCODE field from each of the three CONTHIST tables instead of your formulas. (Based on your sample formula, you may have to either tweak your selection criteria or use a formula instead of the field in order to get the {CONTHIST.ACTVCODE}="MDO" part of your formula.)
-Dell