Fluxbox: How to Launch Applications in Specific Workspace at Startup

This will prompt for a manpage and open it in xterm:

read -p 'which man file would you like to open? '
xterm -e man "$REPLY"

This will run the prompt in a new instance of xterm:

xterm -e sh -c 'read -p "which man file would you like to open? " && man "$REPLY"'

You can use a small BASH script to do that:

This opens a new workspace (taken from here) and runs a command:

#!/bin/bash
i3-msg workspace $(($(i3-msg -t get_workspaces | tr , '\n' | grep '"num":' | cut -d : -f 2 | sort -rn | head -1) + 1))
sublime-text

Create this script under /usr/bin, name it eg. sublime-new, give it exec permissions and you can now launch it from a terminal emulator. Strange, but when executing the script from dmenu, it first opens the program and then changes the workspace.