replace one backslash by double backslash

Hello! I need to provide search only in earliest source in my sourcetype. I use this search request for this purposes: sourcetype="mysourcetype" | stats earliest(source) as firstsource | search source=firstsource But I get error "No results found". I found that the firstsource of returns in the form of D:\MyFolder\Mysourcename.gz while for a successful search must have a value as D:\\MyFolder\\Mysourcename.gz How can I replace \ to \\?