nsdialogs - how to disable control

I am trying to move from installoptions and MUI to nsdialogs and MUI2. In my script I need to disable toggle button (SHOWREADME) on Finish page based on certain condition. In old code I have

WriteINIStr "$PLUGINSDIR\ioSpecial.ini" "Field 5" "Flags" "DISABLED"

What is and equivalent of this with nsdialogs? I haven't found anything neither in documentation nor in examples. Similar question could be "How to hide certain control?"

Thanks in advance

.

EnableWindow $ControlHWND 0
ShowWindow $0 ${SW_HIDE}

Thank you!

EnableWindow $mui.FinishPage.ShowReadme 0

is what I wanted. I also had to define function as MUI_PAGE_CUSTOMFUNCTION_SHOW instead of MUI_PAGE_CUSTOMFUNCTION_PRE which was necessary for instaloptions.