Get the email address list

I have a list of Key Id’s obtained from a SELECT (). From that list I get the first results through the expression TOP ().
I want to get the email address list of each Key Id, in another virtual column, and I can’t think how to do it …
Any help?
The expression is as follows:

TOP([Key Id’s List],[Qty])

Thanks a lot

Assuming you want Emails corresponding to the top Key Id’s, a simple SELECT such as SELECT(TableName[Email],IN([_THISROW].[KeyID], TOP([Key Id’s List],[Qty]) )) should do the trick.