Have you tried it? I'll have to make a test case to be 100% certain, but I do expect it to work fine. Just continue from the 9th field (leave the 10th blank) to the next line and go to the 2nd field (leave the first blank).
I would expect you can mix and match the use of THRU with regular lists of grids... as in this example:
USET1, SB, 123, 170, THRU, 180, 197, 205, THRU,
, 216, 376, THRU, 433
I'll try to make a sample if you find this doesn't work for you.
