How do I get rows based on dynamic column selection in JSL

[#1]

In a JMP script I would like to retrieve the rows matching a certain criteria specified by user. I would like to do something similar to this:

Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
r = dt << Get Rows Where( :sex == "M" );
Show( r );

Only where the criteria is selected by the user, i.e. the column ("sex") and the target value ("M") should be dynamic. I have tried this without luck:

colname=Column(dt,"sex");
target="M";
r2 = dt << Get Rows Where( colname == target );
show(r2);

What am I doing wrong?

[#2 · Accepted solution]

Issue is with your colname

Names Default To Here(1);
dt = Open("$SAMPLE_DATA/Big Class.jmp");

colname = Column(dt, "sex");
target = "M";
r2 = dt << Get Rows Where(As Column(colname) == target);
Show(r2);

or in my opinion better option

Names Default To Here(1);
dt = Open("$SAMPLE_DATA/Big Class.jmp");

colname = "sex";
target = "M";

r2 = dt << Get Rows Where(As Column(dt, colname) == target);
Show(r2);

or

Names Default To Here(1);
dt = Open("$SAMPLE_DATA/Big Class.jmp");

colname = "sex";
target = "M";

r2 = dt << Get Rows Where(Column(dt, colname)[Row()] == target);
Show(r2);