Combination of strings in 1 cell based on word found on multiple rows in table

Hi!

I don't know much about Excel but I need a specific formula if you wouldn't mind helping me..

I need Excel to check if E5 or F5 or G5 or ... M5 in sheet 1 contains the same string as A5 in sheet 2.
If it does, I want excel to take the value of B5 in sheet 1 and put it in D5 in sheet 2.
Then I want Excel to check if E6 or F6 or ... M6 in sheet 1 contains the same string A5 in sheet 2 as before.
If it does, I want excel to take the balue of B6 in sheet 1 and put it in D5 in sheet 2 again,
with a ", " seperating the two different words from B5 and B6 in sheet 1.
And then I need Excel to be able to do this about 500 more times, all in D5 in sheet 2.
And then I want the same thing for D6 in sheet 2, starting at row 5 in sheet 1 again.

So, for example if A5 in sheet 2 = "Cream",
the formula I'm looking for should find all rows containing "Cream" in the table E5:M500 in sheet 1
and note whatever is in column A of each row containing "Cream" in sheet 1
and the result should be printed at D5 in sheet 2 like "Budapest, Napoleon, Princess, Semla, ..."
and any other cakes or whatever that would contain cream.

I've attached my file, if that helps.

=IFERROR(INDEX(Blad1!$B$5:$B$603,SMALL(IF(Blad1!$E$5:$X$603=$A5,ROW(Blad1!$E$5:$X$603)),COLUMNS($D$1:D$1))-4),"")

Yes, of course.
Sorry.

If you look at D77 in sheet 2,
it should contain the string
"Smörgås ansjovis, Smörgås räkor, Smörgås sill, Milanopinne, "
since the word at A77 in sheet 2 (ägg)
exists at rows 12, 19, 21 and 36 in sheet 1.

Hence the words at B12, B19, B21 and B36 in sheet 1
is seperated by comma-signs at D77 in sheet 2 as above.

See new attached file.
Thank you in advance.

tim201110 's reply gives you the result you want but not in a single cell.

Concatenate them with formula or use a VBA function.