I can't answer for sure, but .ex4 compiled with old build 509, works in almost all the case with build 6xx. Of course there are certainly exception.
The best thing to do is to try this 509.ex4 and recompile only as a last solution, mainly for non-programmers.
Nope. This is what most people don't understand.
.ex4 compiled with "old" 509 compiler works most of the time, even if you have ShellExecuteA or other DLL calls. See test script attached. Try it on build 6xx.
Only when you recompile, which seems a bad habit for non-programmer, you will begin to have errors and warnings.
int ShellExecuteA(int hWnd,int lpVerb,string lpFile,string lpParameters,int lpDirectory,int nCmdShow);