Hi Aryn,
I am afraid the .nex to .len file can only deal with data with 1 locus. I guess the best bet is really to combine multiple .len files or to use the .pop input file.
The .pop file can be of the form:
2
s s
popA 0010 111
popA 0100 111
popA 0100 100
or
2
s s
popA 0010 999
popA 0100 999
popA 0100 999
popA 9999 111
popA 9999 111
popA 9999 100
the .len file created in either case will be the same.
Sorry about this limitation.
Best,
Joao