Sorry but it doesn't work that way ... when converting an IRA to a ROTH using the form 8606 the total year end balance of all your traditional IRAs are used ... you cannot convert "in a vacume" so the splitting of the one IRA into 2 pieces is not needed. When you convert there are no penalties applied to the converted amount so you have no need to split the IRA into 2 at all but there is no restriction to doing so either if this helps you.
For instance .... if you take a $1000 distribution from the IRA and convert $400 then you will get one 1099-R showing the $1000 distribution and in the TT program you will indicate that you converted $400 leaving $600 as a taxable distribution subject to tax and possibly the 10% penalty. You do not need 2 1099-R forms at all.
