Thanks for the solution but I didnot use this solution because I have received large amount of data this will take to much time to convert
if it is poosible we can do this things through .net or C# or linq
No it will not take much time. It will take the same time as you will do it manually or by any programming language as it’s just format change on whole column and not being done one by one cell. So @lrtetala 's solution should work.