How could I set the frequency to search for the belgium cable? I see many countries.
thx

What do you mean, DVB-C (cable) or DVB-T (terrestrial)?
Different techniques, requiring different tuners...

However, for DVB-T, there will surely be web pages around, mainly from your local TV provider(s).
And for cable, there is a local cable provider, for details on his services.

In both cases, frequencies, data rates, modulation details and channels depend on your local situation.

For both, channel frequencies will follow european standards, normally, but other details aren't the same everywhere.
So, you may need a custom transponder list, which can be made from an existing one by use of your favourite editor, valid parameters and a little effort....

Latest ProgDVB version is told to provide a basic blind scan function:

Changes in current versions:
5.12.6 Add blind search function. But be quite good for IPTV, DVB-T/C...