This is what I did:
1. renamed doit.log to doit.bat
2. modified doit.bat content to the following:

C:\Documents and
Settings\Unitsofia\Desktop>C:\Programmi\WinHTTrack\httrack.exe
-qiC2%%Ps0u1%%s%%uN0%%I0p3DaK0H0%%kf2A25000%%f#f -F "Mozilla/4.5 (compatible;
HTTrack
3.0x; Windows 98)" -%F "<!-- Mirrored from %s%s by HTTrack Website Copier/3.x
[X
R&CO'2008], %s -->" -%%l "en, en, *" <http://USER:PASSWORD@www.scform.unica>
.it/admin/newDefault.jsp?login=yes&online=all?>postfile:C:\\My%%20Web%%20Sites\\Sc
Form%%20251108%%20-%%20federici\\pagine%%20personali%%20federici%%20scform\\hts-post1"
 -O1 "C:\\My Web Sites\\ScForm 261108 - federici - 3"
+www.scform.unica.it/admin
* -www.netsoul.net/* -www.scform.unica.it/admin/login.jsp?command=logout
+*.gif
+*.jpg +*.png +*.tif +*.bmp --catchurl

4. run doit.bat and so the following output in command window:

C:\Documents and
Settings\Unitsofia\Desktop>C:\Programmi\WinHTTrack\httrack.exe
-qiC2%Ps0u1%s%uN0%I0p3DaK0H0%kf2A25000%f#f -F "Mozilla/4.5 (compatible;
HTTrack
3.0x; Windows 98)" -%F "<!-- Mirrored from %s%s by HTTrack Website Copier/3.x
[X
R&CO'2008], %s -->" -%l "en, en, *" <http://USER:PASSWORD@www.scform.unica>
.it/admin/newDefault.jsp?login=yes&online=all?>postfile:C:\\My%20Web%20Sites\\Sc
Form%20251108%20-%20federici\\pagine%20personali%20federici%20scform\\hts-post1"
 -O1 "C:\\My Web Sites\\ScForm 261108 - federici - 3"
+www.scform.unica.it/admin
* -www.netsoul.net/* -www.scform.unica.it/admin/login.jsp?command=logout
+*.gif
+*.jpg +*.png +*.tif +*.bmp --catchurl
Okay, temporary proxy installed.
Set your browser's preferences to:
        Proxy's address:        192.167.141.91
        Proxy's port:   8080

5. set proxy as specified
6. the command window hangs. so I opened a new browser window
7. the window shows a message saying to restore the proxy
8. restored proxy
9. the command window disappeared
10. found in the output folder only a hts-post0 file.
11. is this because I changed the output folder and with the specified options
I only asked only for an update? I tried by adding a --mirror to doit.bat
(right after httrack.exe) but this time doubleclicking doit.bat the command
window didn't show up and the output folder content didn't change (only
hts-post0 was there).

Please, let me know what I'm doing wrong. Thanks.