It looks to me as if you have the 0-10 VDC signal and are trying to get it to a 4-20 mA. The previous examples are for going the other way - if you had the 4-20 mA and needed voltage.
If you want to go from analog voltage signal to 4-20 mA the easiest soulution is to use a signal conditioner. These are from $150 to $300 depending on features, power, etc. They are widely available - APi, M-Systems, Action Instruments, Acromag, many others.