As you need a driver, you will need a simple variable current source to push through your PIN diode a DC current, from zero to a maximum specified current value.
Usually any variable voltage regulator can be used, with a series resistor set to limit the current at a maximum voltage it can reach.
The VVA response is not linear, it typically rises fast from zero mA , then slower to a maximum at e.g. 50 mA.
The maximum DC current usually depends on a maximum RF power your device should control; it is specified for a particular PIN diode.
Drivers recommended by VVA makers typically use opamps with a diode in feedback, in an attempt to linearize the response. You can play with many such circuits, or, you can design a DAC to get the current by a code to get a linear loss response.