Laravel validation with exist function - validation

Question

I have laravel change password code, with fields: oldpassword, newpasword, confirmedpassword
Now to validate the form the newpasword must be the same as confirmedpassword, and the old must be existed for this user in database
this is my view code:
<div class="form-group">
<label for="oldpsw">your current password</label>
<input type="password" class="form-control" id="oldpsw"
placeholder="your current password" name="oldpsw">
#if ($errors->has('oldpsw'))
<span class="help-block">
<strong>{{ $errors->first('oldpsw') }}</strong>
</span>
#endif
</div>
<div class="form-group{{ $errors->has('password') ? ' has-error' : '' }}">
<label for="password">new password</label>
<input type="password" class="form-control" id="password" placeholder="new
password" name="password" required>
#if ($errors->has('password'))
<span class="help-block">
<strong>{{ $errors->first('password') }}</strong>
</span>
#endif
</div>
<div class="form-group">
<label for="password_confirmation">Password Confirmation</label>
<input type="password" class="form-control" id="password_confirmation"
placeholder="Password Confirmation" name="password_confirmation" required>
</div>
my controller:
return Validator::make($data, ['oldpsw' => 'required|string','password' => 'required|string|confirmed','password_confirmation' => 'required|string',
'password' =>Rule::exists('accounts')->where(function ($query) { $query->where('student_no', Auth::user()->student_no);}), ]);
If I want to use |confirmed my field must be as the name of model fillable field, but if I want to check the db existence it requires the field also as the same column in db.
My Db column is:password, what can I do to solve this problem
Edit: I mean for the two cases both fields must to be named: password !