There is a standard which almost all manufacturers use for these connectors, (+) on the inside of the tip. Edirol is the exception to this rule for some reason so they have the (-) on the inside of the tip, and the (+) on the outside.
go to radio shack... they have "adapt-a-plug" sets. You need a cable, a "B" tip, and an "M" tip. Plug them together with on side TIP(+), and the other side saying TIP(-). It's about $20 but you are done in a minute.
Or take the cable that probably came with your battery, and find an "M" tip for the R44, and wire it backwards so the (+) is on the outside and the (-) is on the outside.