Say a 1099-INT which reports interest from both a taxpayer's account and a joint account (together) is received.  In order to allow for MFS returns, Proseries provides a T, S, or J indicator for each line on schedule B.  But in this case, the interest being reported isn't purely T or J, but a mixture.  Now there also is a fourth choice on the menu, "Split Stmt".  That suggests that one could break out a single line item into subparts and assign T, S, or J to each subpart.  But "Split Stmt" is never active on the menu; it is always greyed out.  

Am I correct that "Split Stmt" would provide the functionality I am looking for?  If so, how does one make this choice from the menu active?

I realize, of course, that as an alternative I could split the income from the single 1099-INT into two separate lines on schedule B and tag one with T and one with J.  But that seems to invite trouble as IRS will never be able to match the 1099-INT information it receives with either single line on the return, since the income will be reported on two separate lines in that case.