For general interest the solution was:
#frame
#push myvar
#set myvar open 10.10.10.10
#append myvar USER myuser
#append myvar mypass
run FTP /inv myvar, out $s.#some/ -n
#unframe
you will notice:
1. no PASS instruction
2. the -n option in the command line for FTP which suppresses the user/pass dialog upon connection.
In my macro i will also SINK the FTP process once i know it works and remove the OUT $s.# guardian parameter.
thanks for the tip about FTPCSTM - i might make use of that. this is a multi-user ROUTINE so it needs to be safe.
//Henrik