T-SQL Using a varchar in a select statement

I need to use the return of a function (VARCHAR) as columns in a select statement. For example:

A function fn1 returns a varchar @result='Alice,Bob'. How can I do a query using @r开发者_JAVA百科esult in a select statement, e.g:

SELECT @result FROM B 

and obtain the records of the columns Alice and Bob of another Table.

Thanks in advance

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Try exec('select ' + fn_1() + ' from T')