'import namespaces
Imports CrystalDecisions.CrystalReports.Engine
Imports CrystalDecisions.Shared

'Declarations
Dim CRPT As New CrystalReport1()
Dim CRFRMDEFS As FormulaFieldDefinitions
Dim CRFRMDEF As FormulaFieldDefinition
Dim LOOPFRM As Integer
Dim FRMNAME As String

CRFRMDEFS = CRPT.DataDefinition.FormulaFields

'Until all Formulas
For LOOPFRM = 0 To CRFRMDEFS.Count - 1

'Get current formula
CRFRMDEF = CRFRMDEFS.Item(LOOPFRM)
FRMNAME = CRFRMDEF.Name

'Set it by Name
Select Case FRMNAME
Case "FRX1"
CRFRMDEF.Text = "{TABLE.FIELD} * 10"
Case "FRX2"
CRFRMDEF.Text = "{TABLE.FIELD} * 20"

End Select

Next

CrystalReportViewer1.ReportSource = CRPT