Has anyone written custom translation rules?

"Dim strFlowType As Boolean = api.flow.switchType(api.Pov.flow.memberid)
Then for the asset/liability sections, replace the three lines with this condition that takes into account switch type.
If strFlowType Then
strRateType = ""AverageRate""
Dim rate As Decimal = api.FxRates.GetCalculatedFxRate(strRateType, curTimeID, args.FxRateArgs.SourceCurrencyId,args.FxRateArgs.DestCurrencyId)
Return New FxRateResult(rate)
Else
strRateType = ""ClosingRate""
Dim rate As Decimal = api.FxRates.GetCalculatedFxRate(strRateType, curTimeID, args.FxRateArgs.SourceCurrencyId,args.FxRateArgs.DestCurrencyId)
Return New FxRateResult(rate)
End If"