http://sourcetreeapp.com/download/
https://downloads.atlassian.com/software/sourcetree/windows/ga/SourceTreeSetup-2.3.5.0.exe
((\d*|.)*)(?=.exe)
{url:regex:((\d*|.)*)(?=.exe)}
2.3.5.0
http://sourcetreeapp.com/download/
https://downloads.atlassian.com/software/sourcetree/windows/ga/SourceTreeSetup-2.3.5.0.exe
((\d*|.)*)(?=.exe)
{url:regex:((\d*|.)*)(?=.exe)}
2.3.5.0
This should work too.
{url:regex:([\d.]+)(?=.exe)}