Hi Harro,
Yes i wanto to do it your sample. but it gives error to me i've modified some sections but was not succesful.

here is the modified code

CLOSE ALL
CLEAR all
SET SAFETY OFF 
clea
Path = "c:\"
FileName = "cs_03-06" && 
? "Process: ",FileName 
select 0
import from (Path)+(FileName)+".xls" type xl8
***************************************************************
* Rename Fields from A,B,C,... to the first line of Excel-Sheet
? ALIAS()
BROWSE

SELECT ALIAS()
anz1 = afields(feldertab) && create Array (fieldnames of dbf)
zwi = "alter table ALIAS() " && build "Alter Table" statement 
for lauf = 1 to anz1 && build "Alter Table" statement
zwi = zwi + " rename column &feldertab(lauf,1). to " + ;
alltrim(&feldertab(lauf,1).)
endfor
? zwi && only for Test; display generated statement
&zwi && do Alter Table
delete && set delete flag for record with fieldnames
pack && delete physical record with delete mark 

&zwi gives error "syntax error"