Actual the max value of slider output is limited to 9999
I would like to have it on unsigned int. value 0 to 65,535
Is this possible ?
Also it would be great to have a logarithmic scale available. (like a Volume control)
With this it would be possible to adjust low values more precise while high values are not so important .
A crude method would be using map();
map(param.asInt(), 0,9999,0,65535);
Might cause some weirdness and not have the same resolution but it would work.
heh, that is 16bits resolution! 
How can you distinguish particular set value on touchscreen? Yet you are able to multiply received value (and do other math) in your code. ah, for example the method that @Jamin had just wrote:)
Yes you are right.
That is the reason while I asked for a logarithmic scale.
oh, I see… then just try some functions from avr/math.h library and do what you need to.