If the data returned looks like this:
x
y
z

I would like to print it on one line like this:
x, y, z

How can I achieve this?

{mytable,myfirstfield} + "," + {mytable,mysecondfield} + "," +
{mytable,mythirdfield} + ","     .... and so on

if you place that formulafield in the details-section of a
drilldown-report you will get CSV datasets, but each dataset in one line.
i suppose its impossible to get a "real" CSV list from a drilldown-
report, perhaps you can try to use the export function for that.

good luck

FieldA     FieldB     FieldC     FieldD  
---------  ---------  ---------  --------
Record1
Record2
Record3

I would like to show a "FieldE" that has data from another table.
This data would be all of the values from a single field that relate
to each record on the main report, in comma-separated format.  For
example, if I did a SQL statement to get the related data:

 "SELECT DataField FROM RelatedDataTable WHERE FieldA = 'Record1'"

It would return:

DataField
---------
x
y
z

And I would like to display this data in the main report like this:

FieldA     FieldB     FieldC     FieldD     FieldE  
---------  ---------  ---------  ---------  ------------  
Record1                                     x, y, z
Record2
Record3