[Closed] "extrudeFace" in EditMesh-Modifier – how?

Hi everybody,
I’m new to this list.
Looks very interesting and helpful. But I wasn’t able to find an answer to this question:

Im trying to extrude a set of faces using an “Edit Mesh” modifier.
But I can’t work out the difference between “Editable Mesh” Object and an object with “Edit Mesh” modifier applyed.
from helpfile:

s=sphere()
   convertToMesh s
   extrudeface s #{1..16} 10 100 dir:#independent
   update s

works like charm…
…but what to do, if I want to use it on a box with an “Edit Mesh” modifier applied?
Three hours of searching and trying resulted in “time to go home and have a beer…”

I really would appreciate some help here.
Thanks in advance
cheers
Ulrich