How to dynamically get path to HTML file in VSTO project for Outlook add-in - vb.net

Question

I am creating a simple Outlook 2016 add-in that will allow the users create a new mail message based on a HTML template.
I have created a Ribbon and added a button to it. Here is the click event handler code:
Private Sub btnCreateMail_Click(sender As Object, e As RibbonControlEventArgs) Handles btnCreateMail.Click
Dim app As Application = Globals.ThisAddIn.Application
Dim currentAccount As Account = app.Session.Accounts.Item(1)
Dim mailItem = DirectCast(app.CreateItem(OlItemType.olMailItem), MailItem)
mailItem.SendUsingAccount = currentAccount
mailItem.To = currentAccount.DisplayName
mailItem.BCC = IdentifyContacts()
mailItem.BodyFormat = OlBodyFormat.olFormatHTML
mailItem.Importance = OlImportance.olImportanceLow
mailItem.HTMLBody = GetEmailBody()
mailItem.Subject = "Subject"
mailItem.Display(False)
End Sub
GetEmailBody() function is responsible for reading the template and modify placeholders as required:
Private Function GetEmailBody() As String
Dim strEmailBody As String
Const strTemplatePath = "C:\Users\umute\template.htm"
' Read the template
Using reader As New StreamReader(strTemplatePath)
strEmailBody = reader.ReadToEnd
strEmailBody = strEmailBody.Replace("{TodaysDate}", Date.Now.ToString("dddd dd MMM yyyy"))
strEmailBody = strEmailBody.Replace("{Name}", GetCurrentUser())
strEmailBody = strEmailBody.Replace("{Greeting}", DetermineGreeting())
reader.Close()
End Using
Return strEmailBody
End Function
The above code works perfectly, however, I am not sure how to get the path to the template file dynamically, that is without entering the full path including C:\Users\ etc. This is because I would like to ship the template file with the add-in to avoid relying on the user to keep it in their local hard drive.
I know that in ASP.NET it is possible to use Server.Mappath("~/file.html") to accomplish this but I don't know the equivalent of this when writing an add-in for Outlook.

Answer 1

After hours of trying, I figured out that the correct way to reference a file is to add it as a resource.
I added a new item of type Resource to the project and added the html template to it. Then, accessed the file like this:
Dim strEmailBody As String = My.Resources.AllResources.Template