lookup_ext using variable lookup table

I would like to use the lookup_ext function, but the table used for lookup should be set by a global variable.

I try to put in a Global Variable in the 'lookup table' field, but when I do this I get the message 'The lookup table is not correct. Correct the problem'.

There are workarounds:

- Instead of using the lookup_ext function I could use a SQL transform, like this:

Something similar is possible in table joins, where you can use the SQL transform like this:

select field_1,

             field_2,

             field_3

   from [$GV_TABLE_NAME]

Alternatively, I could use a flat file and put in a global variable for the file name and path, like this:

(FF_SCHEMA.[$GV_FILEPATH_NAME])

These are useful, but I would prefer to use the lookup_ext function......

Thanks for your suggestions,

Jan.