[NTG-context] request for a quick & dirty hack: shift accents in compose=yes

Hello, I'm using a feature "compose=yes" \definefontfeature [default] [liga=yes,kern=yes,tlig=yes,compose=yes] in a handwritten font to get ccarons (font SnellRoundhandLTStd-Scr.otf). However the carons are placed way off to the right due to the nature of handwritten font. Is there any simple, very-quick-and-dirty way to fix ConTeXt sources (I need it very soon), so that carons would be placed a bit more to the left? (I don't mind to do it just for this single document and then forget about it?) Thanks a lot, Mojca