List cells where value is found: howto?

[dakke]

I have a worksheet with 2000 rows, 3 columns: Worksheet1
Another with up to 6000 rows, 5 columns: Worksheet2

I need a list on worksheet1, that returns all values in column 1 of worksheet2 where the values of column 2 of worksheet 1 is found. To give an idea:

worksheet 1.jpg
worksheet 2.jpg

Result should therefore be: display those rows where in the second column of worksheet2, the value of worksheet 1 is found and return the first column of worksheet 2. (in this example 1,2,3,7,9,10).
Not by indexing them all together, but by listing each separately as in the example is shown.

Please do help me out on this, it would save me a massive amount of time.

I thought of using index, search, array things, but could not find an elegant solution. Any thoughts?

[dakke]

I added a file with the worksheets, and the desired result

example.xls.zip