Fade-out category ID in freetext requirement screen

Hello,

I try to fade-out the category ID field for a freetext requirement without a modification. After some customizing settings it worked fine for the detail screen in the shopping cart, but I also want to fade this field out (or at least disable it) in the popup window.

Web dynpro component   /SAPSRM/WDC_DODC_SC_I_DES

Any ideas to fade out or disbale this field without modofication?

Thanks

Hubert