Dlgchoose and usercommands

Help & Support
1

How can I choose and execute a usercommand with dlgchoose? First line is clear, but how to call variable "var" which includes the usercommand?

@set var = {dlgchoose|Chosse usercommand:|command1=uc1+command2=uc2}
2

Example from help:
@set dir = {dlgstring|Enter new folder name to copy files to}
createfolder ".{$dir}"
copy to".{$dir}"