If your workstation is running some batch job and you don't have any other display session to execute command, you can use the 'send a message option' from the system request menu to execute the command.
That program allows you to send a message to a message queue by using the System Request key with option 5 (Send a message). That can be done even while your workstation is input-inhibited. By using that program, the 'Send a message' option can be used to send a command that gets executed by the operating system. The following command must be executed before MYCMD can be used, ADDLIBLE LIB(qtemp) Crtmsgq msgq(qtemp/q) Chgmsgq msgq(qtemp/q) dlver(*break) pgm(mycmd)