May I suggest that you add padded zeroes to the target <row><column>
string data in the .ti2 file? i.e change A1 to A01 or A001.
The next release has the option of specifying the patch indexing sequence
in printtarg. This is aimed at making it possible to read other charts
(e.g. ECI2002) using their native patch labelling, but would also
allow you to specify leading zeroes if you like.
