Most remotes made by UEI (One-for-all, some RCA, Inteset, and OEM cable TV remotes) can be programmed with "secret codes" for discrete on/off and input commands directly from the keypad, no computer required (we call them EFCs or magic codes). These remote range from about $3 on ebay to $25 retail. So you could use a cheap remote to teach another cheap remote (or simply replace that cheap remote with a far more functional cheap UEI remote).

I use device called the IR Widget which captures, analyzes and produces codes that can be keyed into a UEI remote which could then be used for teaching. Those remotes can also be programmed or read by a PC via an $8 cable from ebay. That's using JP1 software called Remote Master, IR Scrutinizer and IR Scope. In that case a cheap UEI (JP1) remote could be used instead of a Widget.

IR Scrutinizer may be able to read and translate Lirc format to other formats, but I'm not sure about that. To do what you suggested would require an IR transmitter, which most computers do not have.