FILTER/COMPARE BLANK/NULL STRING FIELDS

[#1]

Greetings gentlemen and ma'ams!!!

I am trying to bring only fields that are not blank or null during a LOAD / LEFT JOIN statement, but unsuccesfully.

The code follows below:

LOAD Customer_Shipper , SUM (Teus) AS SUMTEUS

FROM [..\..\Qvd\CSAV_BRASIL\MercadoECSA.qvd](qvd) ;

LEFT JOIN LOAD Shipper AS Costumer_Shipper , [Partner Code]

FROM [..\..\Datos Externos\CSAV_BRASIL\dicionario mercado-csav\dicionario.xls] (biff, embedded labels, table is Sheet1$ )

WHERE NOT EXISTS(Costumer_Shipper,'')

GROUP BY Customer_Shipper, [Partner Code];

and the following errors are dysplayed after running the script:

...as far as I can see, my code doesn't seem to be out of logic, and I just can't figure out what's wrong...

Could someone shed some light upon this, PLEASE???

In advance, my apologies if this is an seely question (official noob here).

Thx!!!

[#2]

Guys, there are duplicate posts by me on the forum... It happened by a server timeout error during the post process... is there a way to delete them?

Regards!