Lookup function

Hi All,

I'm trying to join two Datasets, so I would be able to retrive the correct Data depending on if the criteria is met; for example:

=Lookup(First(Fields!countrycode.Value, "DataSet1"), First(Fields!countryCode.Value, "DataSet2"),
(First(Fields!sourceCode.Value, "DataSet2")

but I keep getting the following error messages:

[rsExpressionMissingCloseParen] There is a syntax error in the Value expression for the textrun ‘Textbox52.Paragraphs[0].TextRuns[0]’: ‘)’ expected.

Or is there another function I can use to get the Data out please?

Thank you!