you are inconsistent one place you say 13H the other 13W. 13W should work and flow to schedule E. However I would say if the only income reported was on line 5 - interest income - then the interest expense should be code H.
for 13H investment interest expense flows to form 4952 which calculates the allowable deduction. the allowable amount flow to schedule A-line 9. so you must have enough net investment income and also itemize your deductions to benefit from this expense. people who don't itemize lose out because the investment income remains fully taxable while they get no deduction for the IIE.
