How do I find unique items from a two dimensional range

[mike szczesny]

I already have a crazy complicated formula that list items from a two dimensional range. How would I need to incorporate the frequency formula part in this formula. The formula is:
assume 100,500,1000 are in R19:R21 (using index,small(if(frequency(if...... formula
Assume this formula below in S19. formula to be copy across
=IFERROR(INDEX($S$4:$AA$17,INT(SMALL(IF($R$4:$R$17=$R20,(ROW($S$4:$AA$17)-ROW($S$4)+1)*10^9+COLUMN($S$4:$AA$17)-COLUMN($S$4)+1),COLUMNS($R$19:R20))/10^9),MOD(SMALL(IF($R$4:$R$17=$R20,(ROW($S$4:$AA$17)-ROW($S$4)+1)*10^9+COLUMN($S$4:$AA$17)-COLUMN($S$4)+1),COLUMNS($S$19:S20)),10^9)),"")
This formula list all item for 100, first by row, then next row, etc

Assume data range is R3:AA17 (including column descriptions)
COl A COL B COL C COL D COL E COL F COL G COL H COL I COL J
100.00 2 3 4 5 6 7 8 9 0
100.00 0 1 2 34 4 5 6 7 8
100.00 a b c d e f g h i
100.00 j k l m n o p q e
100.00 y t r y j g b j l
500.00 m m m m m m m m m
500.00 n n n n nn n n n n
500.00 b b b b b b b b b
500.00 v v v v v v v v v
1000.00 t t t t t t t t t
1000.00 r r r r r r r r r
1000.00 o o o o o o o o o
1000.00 p p p p p p p p p
1000.00 q q q q q q q q q