Sorry, I though you had the first part already. Here it is in bash.
#!/bin/bash
# set these to the appropriate directories
HOLD=~/HOLD
CUSTOMERS=~/CUSTOMERS
for FILE in $HOLD/*; do
# get the customer number
CUSTNUM=`echo $FILE | awk -F\- {'print $2'}`
# check if the customer dir exists, if not create it
if [ ! -d $CUSTOMERS/$CUSTNUM ];then
mkdir $CUSTOMERS/$CUSTNUM
fi
# move the file
mv $FILE $CUSTOMERS/$CUSTNUM/