Thank's any way.

I have a MAX232 in between so the voltage level should be
no problem.

I might be still wrong in pin connections, because
the source still ambiguis.

I read them from the following links:
1. www.jikos.cz/~jbohac/goodies/patchingsiemens55.html
2. www.usbdeveloper.com under gsm page

I choose C35 because it is cheap now on street market
(Its around $20).

Jan Waclawek, I think you know the pins assignment
of the data cable, would you please open it in the
forum, or use the my email address ( mikronik@mdn.prime.net.id )

Thank you very much.