How to do this on C#.NET

[scriptick]

Hello,
I was write a class on VB.NET and i wanna move my project on C#.NET. I know VB.NET class can be converted to DLL.
I also do that but i have a problem with just one line code :

On the class i wrote a code like this :
MyProject.Forms .frmMain.ComboB ox1.Items.Add(m odKb.Items(i).N ame)

More Details :

    Public Class modLay
        Public Shared Function Add() As Boolean
            Dim flag As Boolean
            Dim directory As String = (myFunctions.VerifyPath(MyProject.Application.Info.DirectoryPath) & "Items")
            If Not MyProject.Computer.FileSystem.DirectoryExists(directory) Then
                Interaction.MsgBox("'Layouts' folder not found", MsgBoxStyle.Critical, Nothing)
                ProjectData.EndApp()
            End If
            Dim onlys As ReadOnlyCollection(Of String) = MyProject.Computer.FileSystem.GetFiles(directory, SearchOption.SearchAllSubDirectories, New String() {"*.xml"})
            If (onlys.Count = 0) Then
                Interaction.MsgBox("No file found under 'Items' folder", MsgBoxStyle.Critical, Nothing)
                ProjectData.EndApp()
            End If
            modKB.LayNumber = (onlys.Count + 1)
            modKB.Lay = New clsLayouts(((modKB.LayNumber - 2) + 1) - 1) {}
            Dim num2 As Integer = (modKB.LayNumber - 2)
            Dim i As Integer = 0
            Do While (i <= num2)
                modKB.Lay(i) = New clsLayouts
                modKB.Lay(i).Init(onlys.Item(i))
                modKB.Lay(i).Path = onlys.Item(i)
               
               MyProject.Forms.frmMain.ComboBox1.Items.Add(modKB.Lay(i).Name)

                Catch exception1 As Exception
                    ProjectData.SetProjectError(exception1)
                    Dim exception As Exception = exception1
                    ProjectData.ClearProjectError()
                End Try
                modKB.Lay(i).ID = i
                item.Tag = (i + 2)
                i += 1
            Loop
            Return flag
        End Function

Now my question is :
How to i call this code"genCombo.I tems(i).Name" from dll (When i using that dll on C#.NET) ?

I can call the function but how to add item on C#.NET project ?