Hi, it's simple... It's not possible to do it as you say...
However there may be an acceptable solution for you. You can print the pdf as you did it before. In the pdf, there will be only image of the file. Now you have several options what to do
1) You can keep the file you wanted to embed as a separate file and manualy create link to this file in Acrobat. There is direct option how to do this.

2) If you want to embed the file, you can embed it again in Acrobat, and then create a link manually, but there is no direct option how to open embeded file by clicking that link...
So you can either set the action to execute a command from the menu, and set the command to open the form with attachments (this will not open the file, it will just open the window with attachments...)
or
you can set the action to execute javascript and write some script by yourself that will open embeded file. This is probably most complicated solution, but it's the only solution that 100% performs what you want...