Crystal Reports Display Array as comma delimited

Message

     I am trying to set up an array that will display a list of item numbers (LPNS) in a group footer. I have this formula in the report header:

WhilePrintingRecords;
Shared NumberVar ArraySize;
Shared StringVar Array LPNS;
ArraySize := ArraySize + 1;
ReDim Preserve LPNS[ArraySize];
LPNS[ArraySize] := {LPN_HISTORY.DC_LICENSE_PLATE_ID};
''

Then I have this formula in the group footer:
WhilePrintingRecords;
Shared StringVar Array LPNS;
Local NumberVar i;
Local StringVar MyOutput;
For i := 1 to UBound(LPNS) do
   MyOutput :=  MyOutput & LPNS & chr(13);
MyOutput

The field is set to grow, but is only displaying the very first LPN when there should be 36.

I want to display them in the footer like this and just have them wrap at the full width of the report:
10671314, 10671315, 10671316, 10671317, 10671318, 10671319, 10671320, 10671321, 10671322, 10671323, 10671324, 10671325, 10671326, 10671327, 10671328, 10671329, 10671330, 10671331, 10671332, 10671333, 10671334, 10671335, 10671336, 10671337, 10671338, 10671339, 10671340, 10671341, 10671342, 10671343, 10671344, 10671345, 10671346, 10671347, 10671348, 10671349

I copied a formula I found somewhere else that hopefully just needs tweaked. How can I do this?