Lookup_ext function not working in validation transform

Dear Experts

   I have requirement to create multiple rules inside the validation transform. All the rules i need to create is a lookup_ext function with multiple column validation. I create the same logic in query transforms its works fine. But when i use the same logic inside the validation transform with custom function its giving me the error. Kindly help to achieve it correctly.

  The automatic code generated for lookup_ext

lookup_ext([SE1EXTR.SE1EXTR.SE_KNVV_TABLE1,'PRE_LOAD_CACHE','MAX'], [KUNNR],[NULL],[KUNNR,'=',Query."Sell-to Customer No_",VKORG,'=',Query.SALES_ORG,VTWEG,'=',Query.DIST_CHAN,SPART,'=',Query.DIVISION],[],[New_Kunnr]) SET ("run_as_separate_process"='no', "output_cols_info"='<?xml version="1.0" encoding="UTF-8"?><output_cols_info><col index="1" expression="no"/>

</output_cols_info>' )

The screen shot gives the correct error message.

Thanks and Regards

Vijay Mukunthan