Just to contribute to the discussion, here is a .xk1 file. I don't have any files with the .xkp extension. It seems like the macro maker gives a number depending on which model the macro file is for. xk1 is for Desktop, xk2 is for Pro.

[code:1]
1
0,0,1,"a1",0,0,0,"0004,1004,0030,1030,"
1,0,1,"b1",0,0,0,"0005,1005,0030,1030,"
2,0,1,"c1",0,0,0,"0006,1006,0030,1030,"
3,0,1,"d1",0,0,0,"0007,1007,0030,1030,"
...
...
16,0,1,"a5",0,0,0,"0004,1004,0034,1034,"
17,0,1,"b5",0,0,0,"0005,1005,0034,1034,"
18,0,1,"c5",0,0,0,"0006,1006,0034,1034,"
19,0,1,"d5",0,0,0,"0007,1007,0034,1034,"
0,1,0,"",0,0,0,""
1,1,0,"",0,0,0,""
2,1,0,"",0,0,0,""
3,1,0,"",0,0,0,""
...
...
[/code:1]

This is what it looks like opened in a text editor. It seems the codes are four digit numerics (HID codes?), with the first being a 0 or 1 for down or up. If you can figure out the codes they're using for the keys, you can just edit it in plain text.