Hi Everybody!
funny, after typing down the question i found a solution 
it was quite simple: i just created a bool variable called “gettingJumpPrepared” in my character BP.
so when i press the spacebar this value gets set to true. after that, a delay(which represents the anticipation time) starts. after the delay the normal jump function/command gets executed.
in the animation blueprint i use a cast to my character blueprint and get the “gettingJumpPrepared” variable.
If the variable is set to true the jump animation starts.
Best regards
CYTE =)