go into the mixer section & press rec+start wile youre in the mix,
and as it records start moving the level for youre sample whenever desired..
if this do not work go into the mixer section setup and adjust the recording adjustment ( do not remember whats the name for it but read and you`ll find it !)
thanks for your fast answer and sorry for my english because i'm french...so my question was:is it possible to record into the sequencer the mix level change,and how to do it......Thanks to you all.....