Set an environment variable to a new value, similar to the shell's export or setenv command. The variable and its value are inherited by processes started directly by fvwm. This can be especially useful in conjunction with the FvwmM4 module. For example:

SetEnv height HEIGHT

makes the FvwmM4 set variable HEIGHT usable by processes started by fvwm as the environment variable $height. If value includes whitespace, you should enclose it in quotes. If no value is given, the variable is deleted.