The perfect solution is to get the RES-1 from Kele Inc. It will take a 0-10 VDC Input and convert it to a simulated RESISTANCE Output, you select the resistance range: 0-135, 0-270, 0-500, or 0-1000 Ohms.
The Model RES-1(RES-1E in Fall) Universal Resistance Transducer provides a precision resistance output for DDC control of electric actuators or other electronic devices that operate from a variable resistive circuit. Various jumper-selectable analog and pulse-width modulated (PWM) inputs are available, and the transducer may be powered from 24 VAC/DC. The Model RES-1 is furnished with snap-track for easy mounting and may be operated in a multiplexed PWM mode so that one BAS output may address up to eight Model RES-1s.
http://www.kele.com/webservices/index/index.aspx?cat=10245&sec=ot8
The Model RES-1(RES-1E in Fall) Universal Resistance Transducer provides a precision resistance output for DDC control of electric actuators or other electronic devices that operate from a variable resistive circuit. Various jumper-selectable analog and pulse-width modulated (PWM) inputs are available, and the transducer may be powered from 24 VAC/DC. The Model RES-1 is furnished with snap-track for easy mounting and may be operated in a multiplexed PWM mode so that one BAS output may address up to eight Model RES-1s.
http://www.kele.com/webservices/index/index.aspx?cat=10245&sec=ot8