For me, Excel is in the path and I can imagine that WordPad is always in the path, it being part of the OS.

So you can start the programs with

system("excel");
system("wordpad");
[download]

If you want to check for program existance first, try manually iterating over the parts in $ENV{PATH}.

In the case that Excel for some reason isn't in the path, there is probably some registry key for that... Try searching in your own registry (although that may differ between versions).

/J