sets
i
j  ;

parameter c(i,j);


$onecho > testtable1.txt
dset=i   rng=a1  rdim=1
dset=j   rng=a1       cdim=1
par=C  rng=a1 rdim=1 cdim=1
$offecho

$call GDXXRW testtable1.xlsx  @testtable1.txt
$GDXIN testtable1.gdx
$load i,j
$load c
$GDXIN


parameter P(i,j);
P(i,j) = 2*c(i,j);


execute_unload 'output2.gdx';
execute 'GDXXRW output2.gdx par=p rng=sheet1!a1';

display C;