Lookup value and match with 2 criteria and return another value

Hi All,
I would like to do a Lookup and match with 2 critera and return a third value.
On my sheet 'DATA' in cell "C2" I would like to lookup and match the order no "O/N" & 'INVTOTAL" and find the "INV No" on sheet 2.

Sheet1 "DATA" contains;
O/N INVTOTAL INV No SUPERVISOR POSITION EMPLOYEE INV DATE TOTAL
U11888 1759.62 ? MERV MAHER LEVEL 9 WEBSTER Joshua 1st JUL 2009 284.75

Sheet 2 "INVOICES" contains;
O/N INV TOTAL INV No DATE NET GST DIV SUPERVISOR
U11888 1759.62 63008 1/07/2009 1599.65 159.97 BURLEIGH MERV MAHER

Your help is much apreciated.
Craig

Thank you Vlady that did the job.
Sorry I didn't reply yesterday I was called away.
Thanks again.

Craig