To open a workbook from another workbook

wbkId =  “MP06Z6R6OOJ6YKYIQZN3IQ38Y”

retVal = Run(“BexAnalyzer.xla!SAPBEXreadWorkbook”, wbkId)

http://h30499.www3.hp.com/t5/Performance-Center-Support-and/SAP-Bex-7-VBA-LoadTest/td-p/4346563