I need to open multiple files without opening the same program several times. How can I open several files, using only one shellexecute call.

The following code works put opens two instance of the aplication.
I need only one instance of the aplication


sfile1="C:\data.pdb"
sfile2="C:\prod.pdb"

ShellExecute Me.hwnd, "", sfile1, sCommand, sWorkDir, 1
ShellExecute Me.hwnd, "", sfile2, sCommand, sWorkDir, 1


Please help...