using decimal (,) sign instead of point (.)

I try to use your plugin to add additional cost to a few products and I want to add comma-seperated numbers because I can’t use the point as a separator for prices but I can’t get it to work. Does your plugin only work with points (.) I only get the plugin to work with whole numbers like 2 or 3 or 4 and not with 2,45 or 3,25 etc.

Thanks for your reply in advance

Niek from the Netherlands