calculating salary

hi i am working in a Pvt org as a Special educator - teacher category. the excel sheet that i came across seems to make things simple and easy. i am bad with numbers but with hard earned money learning about it is something i am still struggling. i am having a disability certificate plus the PF section in the excel sheet shows an amount that probably requires to be there but i am paying less than that. i have tried using the site : Copy of Income_Tax_Calculator_2010-11.xls is there some software where i could add in my data and special concessions example stating the disability - polio with scoliosis impacting on mobility only.