Different permalinks for few categories???

I’ve been killing the category base from my blog which results my two of my subcategories giving 404.. however they are accessible if i place the category within the url like

http://www.mydomain.com/category/parentcategory/subcategory

right now the url looks like

http://www.mydomain.com/parentcategory/subcategory

is there anyway that i can inject “category” within the url without disturbing the rest of the categories?

any idea fellows?