Apache poi event api issues

Hi i am developing the app conversion of xlsx/xls to csv using apache poi event api.I am facing some issue please clarify .

For accounting column

While reading from xlsx :
format index is = 44
format string is =_("$"* #,##0.00_);_("$"* \(#,##0.00\);_("$"* "-"??_);_(@_)
output is coming correct = $ 20.00

but while reading from xls:
format index is = 44
format string is =_(* #,##0.00_);_(* (#,##0.00);_(* "-"??_);_(@_)
output is coming wrong= * 20.00

Can u tell why it is coming wrongly.