Compiling Paragraph returns in Windows Scrivener?

Is there a way to replace single line returns with double line returns when you compile to multimarkdown? I’ve tried various things in the ‘replacements’ panel, none of which work. It’s my understanding that “OPT-return” or “OPT-enter” work in the Mac version of Scrivener. Is there a Windows equivalent? I’ve tried regular expressions like replacing \r\n with \r\n\r\n, I’ve tried replacing ^p with ^p^p, I’ve tried CTRL+LF variations, and more. I’ve tried CTRL-return and CTRL-enter, ALT-return, and Shift-return, etc. But no luck. The only thing that has worked is compiling to an mmd file and opening that file in a code editor (Notepad++, Sublime, Komodo, etc) and doing a search and replace on \r\n to \r\n\r\n.

Thanks for any info…