I want to be able to open a file without stating the application to
open it. Not unlike adding a hyperlink to a cell value.

Only, I want it done in VBA since it must take some variables. The
following works great if the path to the application is known.

Dim x As Variant
x = Shell( AppPath & " " & FilePath, 1)

However, i want it to take the windows default application to open the
file. Again, much like the result a hyperlink produces. Simply
omitting the AppPath results in an Error 5, something like "invalid
procedure call or invalid argument".

EDIT: found a solution that works for me:

http://chrisrae.com/vba/routines/shellexecute.html