is there any way to amplify the current by the factor of 2^(8) in the PSoC.
Yes, classic OpAmp current source/sink can be done with onchip
OpAmp and external Rsense and a discrete transistor. Using onchip
VDAC one could drive that into aforementioned solution and effect
1) Is your current DC only ?
2) Accuracy of desired current ?
3) Complience range of source/sink needed ?