style='vnd.ms-excel.numberformat:#,##0.00_)[semicolon][Red](#,##0.00)'
Example use:
Print "<tr>" & _
"<td>" & pdoc.LastName(0) & "</td>" & _
"<td>" & pdoc.FirstName(0) & "</td>" & _
"<td>" & pdoc.MiddleInitial(0) & "</td>" & _
"<td>" & pdoc.EmployeeID(0) & "</td>" & _
"<td>" & pdoc.TaxYear(0) & "</td>" & _
"<td>" & pdoc.EarningsReportSection(0) & "</td>" & _
"<td>" & pdoc.Account(0) & "</td>" & _
"<td>" & pdoc.Paid_mm(0) & "/" & pdoc.Paid_dd(0) & "/" & pdoc.Paid_yyyy(0) & "</td>" & _
"<td style='vnd.ms-excel.numberformat:#,##0.00_)[semicolon][Red](#,##0.00)'>" & pdoc.Amount(0) & "</td>" & _
"<td>" & pdoc.Currency(0) & "</td>" & _
"<td>" & pdoc.ExchangeRate(0) & "</td>" & _
"<td>" & pdoc.Currency(0) & "</td>" & _
"<td>" & pdoc.CurrencyCode(0) & "</td>" & _
"<td>" & pdoc.PayCode(0) & "</td>" & _
"<td>" & pdoc.ChargeUnit(0) & "</td>" & _
"<td>" & GLBookDateValue & "</td>" & _
"<td>" & GrossUpOptionsValue & "</td>" & _
"<td>" & pdoc.Comments(0) & "</td>" & _
"</tr>"