www.hifi-remote.com/forums/dload.php.  This file was submitted by Rob Crowe, who is a true guru of IR remotes, so it likely did correctly control a Plus U2 projector.

However, it may not be immediately apparent to you, but 0xe9 and 0x16 are complements of each other--they add up to 0xFF.  That is significant in this context.  The original NEC protocol was designed to provide an 8 bit custom (device) code, and an 8 bit function code.  But 16 bits were allocated to each, and the second 8 bits of both custom and function numbers are the complements of the first 8 bits.   Later, as companies needed more device number space, they began to use all 16 bits of the custom code, and no longer obeyed the complement rule. 

There's more.  IR is a serial protocol, and there is no real standardization of which signal is a 0 and which is a 1.  When experimenting with IR signals, it is reasonable to try the complement of every 8 bit number.

Still more:  A serial protocol can send the least significant bit first or MSB first.  So let's take Discrete Off, function number 20 decimal (0x14).  The necessary input to your program may be 18E9 (custom) + 14EB (function) or E7E9 + EB14 or......

Function number 20 decimal (14EB) could be represented by D728, which is bit reversed order, or 28D7 (bit reversed and complemented).

The numbering convention is the same for UEI remotes and Pronto Hex formats.  But it is mostly arbitrary, and your program and Plus projector documentation may treat it differerently.

Discrete On is function number 8 (or 0x10--bit reversed, or 0xF7--complement, or 0xEF complement, bit reversed)
Off is function number 20 -- 0x14  (or 0x28 or 0xEB or 0xD7