How to split the string of MembershipCreateStatus to multi-word? maybe you should use regular express.

I hope to convert MembershipCreateStatus to a string, but I hope to split the string to multi-word by upper case, such as "InvalidUserName"=>"Invalid User Name", how can I do? Thanks!

Now I use a complex way.
 

MembershipCreateStatus status;
Membership.CreateUser(userName, password, email, question, answer, true, out status);
string s="";
switch (status)
{
     case MembershipCreateStatus.Success:
     s="Success" 
     break;
     case MembershipCreateStatus.DuplicateUserName:
     s="Duplicate User Name"              
     break;
     case MembershipCreateStatus.InvalidUserName:
     ...