It is up to you but my guess is just use the dates. definately do not use the status as it is dynamic and only reflects the last update not any status it may have been in which is what you want.
Most likely your condition for Open is
did the Open_date fall in your paramter range (yes include, no exlcude) so later this formual to make the fierlds be the real items from your report
if table.opendate in startdate to enddate then 1 else 0
Sum this formula field at ther report level fo get a total # of opened in range
Most likely your condition for Closed is
did the Close_date fall in your paramter range (yes include, no exlcude)
Close count formula
if table.closedate in startdate to enddate then 1 else 0
Sum this formula field fo get a total # of closed in range
Or is you want to use Running Totals (RTs) they can use a conditional inclusion. It evaluates to True or False. (If TRue include if False Exclude). This is placed in the Evaluate section of a RT under Use a formula (click onthe x-2 and palce in there)
You need 2 RTS. OPenCount and CloseCount
OpenCOunt
Field to summarize = chg_ref_num
Type of SUmmary=Count
Evaluate, select Use a FOrmual and add in
table.open_date in startdate to enddate (repalce with real field names)
Reset set to Never.
Place on report Footer.
repaet process for ClosedCount but change the formul to something like:
table.end_date in startdate to enddate