The simply answer is no, because FlashFXP does not have scriptability with string functions.
However if you are sending to an empty folder on the destination server then you can transfer them all as they are, then run some custom commands on them to change the names... but I am guessing this is not what you are doing otherwise you could automate the renaming outside of FlashFXP a million different ways.
Command 1
Code:
{
RNFR %f
RNTO $replace("%f","2000-","")
}
Command 2
Code:
{
RNFR %f
RNTO $replace("%f","-","")
}