Cannot find table WRKTMS_SNPSHT_WC_STRNG_XT_FRM in the data warehouse

In BIRT reporting, we’re using a logical table name called WC_STRING_EXT_FROM. The corresponding table in dw should be WRKTMS_SNPSHT_WC_STRNG_XT_FRM but we can’t find it.

This is basically what we’re doing: 

-          For a given Workitem ID (EXTERNAL_KEY1) we retrieve all the FACT_ID (REQUEST_HISTORY_ID) from the REQUEST_HISTORY table.
-          Then for each FACT_ID we want to get the value of a custom attribute (KEY) for a given TIMESTAMP from the table WRKTMS_SNPSHT_WC_STRNG_XT_FRM.