Good day,
The spreadsheet control doesn't seem to support nested VLOOKUPS eg
=IFERROR(IFERROR(VLOOKUP(alt_ref&"/"&supplierID&"/"&LEFT(courseCode,4)&"*",Calcs!A:G,6,FALSE),VLOOKUP(alt_ref&"/"&supplierID&"/",Calcs!A:G,6,FALSE)),VLOOKUP(alt_ref&"//",Calcs!A:G,6,FALSE))
This works correctly in Excel.
Regards
Derek