Unable to Calculate Currency Override only for Accounts with Text Filter.

You might like to consider this example as a starting point, which looks in C#Local for any populated cells on special flows that have Alternate Currency Input , and copies those appropriate currency inputs into F#EndBal on the corresponding data unit for that translated ccy.

I recommend using the Alternate Currency Input properties of the flows, rather than assuming flow naming convention, to obtain the currency:

				If Not api.Entity.HasChildren() _
				AndAlso api.Cons.IsForeignCurrencyForEntity() Then
					Dim dataUnitCcyId As Integer = api.Cons.GetCurrency(api.Pov.Cons.MemberId).Id
					Dim id_EndBal As Integer = api.Members.GetMemberId(DimTypeId.Flow, "EndBal")

					' --- assumes F#[OverridesParent] is the parent of all flows that have Alternate Currency Input --
					Dim di As ExpressionDestinationInfo = api.Data.GetExpressionDestinationInfo(String.Empty)
					Dim buf As DataBuffer = api.data.GetDataBufferUsingFormula("FilterMembers(C#Local,F#[OverridesParent].Base)",DataApiScriptMethodType.Calculate,False,di)
					Dim resultBuf As New DataBuffer()
					
					'--- now loop through the populated cells for flows that have Alternate Input currencies ---
					For Each bufCell As DataBufferCell In buf.DataBufferCells.Values
						If Not bufCell.CellStatus.IsNoData AndAlso bufCell.CellAmount <> 0 Then
							' -- test if the flow member represents an alternate Input currency ---
							Dim AltCcyIdForFlow As Integer = api.Flow.GetAlternateInputCurrencyId(bufCell.DataBufferCellPk.FlowId)
							If AltCcyIdForFlow = dataUnitCcyId Then
								Dim resultCell As New DataBufferCell(bufCell)
								resultCell.DataBufferCellPk.FlowId = id_EndBal
								resultBuf.SetCell(si,resultCell,True)
							End If
					End If
						
					Next
					api.Data.SetDataBuffer(resultBuf, di)