I need a way to generate over 1200 unique two letter combinations. I've been
reading past posts that explain ways to use the MATCH and VLOOKUP functions
to convert numbers to text, but have not found the solution yet. Any help
would be greatly appreciated.

Hello,

I suggest:

1. Take my function UniqRandInt() from www.sulprobil.com
2. Put at least 35 different characters of your choice into A1:A35 (because
35*351200). More won't hurt. Leave rest of column A empty.
3. Enter into B1:
=COUNTA(A:A)
4. Select the 1200 cells C1:C1200 and enter as array formula (CTRL + SHIFT +
ENTER):
=uniqrandint(B1*B1)
5. Enter into D1:
=INDEX(A:A,1+INT(C1/B$1))&INDEX(A:A,1+MOD(C1,B$1))
and copy down to D1200

HTH,
Bernd