how to define and initialize struc for GUID

I've been struggling with struc all the evening, but cannot make it work

I'd like to define a struc for GUID as follows:

Code:

struc GUID {
  .TimeLow dd ?
  .TimeMid dw ?
  .TimeHighAndVersion dw ?
  .ClockSeqHighAndReserved db ?
  .ClockSeqLow db ?
  .Node db 6 dup (?)
}

the problem is that the structure is not initializable.
For example, I want to init the structure with values

Code:

MyGUID GUID 0x12345678, 0x1234, 0x5678, 0xaa, 0xbb, <0x11, 0x11, 0x11, 0x11, 0x11, 0x11>

or I'd like to define several constants in a .inc file so I could use them like
MyGUID GUID CONSTANT_VAL

The only solution I came up with is to use

Code:

struc GUID [val] {
  align 8
 common
  . db val
}

and initialize GUID byte by byte. But this is not the way I'd like it to be.
Thanks in advance for any suggestions.

struc GUID def { match d1-d2-d3-d4-d5, def \{ .Data1 dd 0x\#d1 .Data2 dw 0x\#d2 .Data3 dw 0x\#d3 .Data4 db 0x\#d4 shr 8,0x\#d4 and 0FFh .Data5 db 0x\#d5 shr 40,0x\#d5 shr 32 and 0FFh,0x\#d5 shr 24 and 0FFh,0x\#d5 shr 16 and 0FFh,0x\#d5 shr 8 and 0FFh,0x\#d5 and 0FFh \} }