Hi Denis,
There's a few things you could improve in your code:
1) There's no reason to do both *RST and FAC
2) DATA:SOU is for curve queries, it's irrelevant here
3) MEASU:AUTO EXEC is for jitter measurements, it shouldn't be used here
4) MEASU:MEAS1:CCRESU:ALLA:MEAN? is for getting the mean value of a measurement across multiple acquisitions, this is not what the procedure is asking for. Instead, you should use MEASU:MEAS1:VALUE?