Use IE and switch on "Compatibility Mode", that will give you some better window to enter your text.
PID controller from UDB and its DataPath will not be too difficult to implement, there are registers, an ALU, 2 FIFOs and more than a handful of instructions. Have a look into your VeriLog handbook that has been installed together with Creator.
You could consider implmenting most of that with DFB Assembler
and DFB block.
Since for PID you need multiplication, this will be difficult to implement in the UDBs (or the DataPath).
Using the DFB as DSP engine should work better, but is more complicated. You also have the issue of getting the output value to where you need it (e.g. driving a PWM or a DAC).