You are not the first one to come across this problem
I've been successful in reading a dir for all its files using ActiveX.
But then I came across another problem. You can't change the values of an <input type=file>. You can't:
a) <input type=file value=File>, it won't accept the value field
b) <body onload=getElementById('fileField').value='File'>
<input type=file id=fileField>
</body>, It will also do nothing.
File fields are not programable, mostly for security reasons, as you would be able to retrieve things from users computers without their permission.