taskbar icon size

[adacom]

is there any way to add more options or flexibility to the taskbar icon size setting - the 4 settings are great but i find the difference between the 2 i use - small and medium too big - one in the middle of those 2 would be ideal - so is it possible to do it by pixel size or a slider to increase the size 

i am assuming its a registry setting but finding it is not something i have a clue how to do - or maybe its done in some other way