well I would do two things

instantiate the variables in header

create four shared variables in formulas to flag a client as in 1/2/3/4 programs

create four running totals to count the number of programs a client is in

group by client

summarize distinct count of programs

in group footer find the count and do a +1 to the shared variable corresponding to number of programs

in report footer reference those shared variables

if you want elaboration I can explain further