I might be missing something, but I think your question is clear. As you're moving through the Flow, you get to a certain point, then you want to specify a new level? At that point, I think you can execute a rule to Assign a constant value (whatever level you want to go to) to the CHANGE_LEVEL. Here's what's in the help file:
"When the user assigns a new value to CHANGE_ LEVEL in a rule command, the program first processes the rule, then goes to the new level specified in CHANGE_LEVEL, and finally resets the value of CHANGE_LEVEL to spaces. [CHANGE_LEVEL and COMBINED_BREAK are used in rule commands to control map flow processing on outbound maps.]"
What version of ECMap are you using?
Someone else might know of another way, but the only way that I know to manipulate system variables is through rules and the Assignment command.