ShowURL mailto citation

Hi, I know how to use mailto to send email, with Cc or Bcc etc. , but I don’t know how to answer to a text.
TextFieldBody.Text contains the text I want to answer to. Then I would like to launch Mail.app with this text in citation, and I write my text above.
I try to add "> " but it does not work.

ShowURL("mailto:" + EncodeURLComponent(TextFieldEmail.Text) + "?Subject=" + EncodeURLComponent("Re: " + TextFieldSubj.Text) + "&body=" + EndOfLine + EndOfLine + "> " + EncodeURLComponent(TextFieldBody.Text.ReplaceLineEndings(EndOfLine)))

Include the EndOfLine + EndOfLine + "> " in the lastEncodeURLComponent.

Thank you, I tried this but I receive the email with “> my text”, I don’t have the horizontal line showing citation.

I wrote Citation but it’s a French word, I mean Quote .