Change event to Convert (calculate) user input if user types % sign

How can I convert a user's input from the input value to something else IF the user typed a value and % sign? In other words, user types 10% in A1, which i capture in the change event. Since user typed % sign, I want to change the original input (10%) to the result of 10% * A2. The problem is for this to work the cell numberFormat MUST be accounting and two decimals. I want the cell format to be 0 instead of 0.00 though.

Below is what I have that works only if the format per below (accounting). It basically takes the user's input and recalculates it as a percent of the amount in the adjacent column..if the user types 10%. Keep in mind the target numberFormat must remain as 0 (and not 0% nor 0.00, which is what the below code must do to work). Any tips are greatly appreciated!

To rephrase:
1. Target must be formatted as a number, eg., 0.
2. If user inputs target value with a % (eg, 10%), recalculate input as 10% * adjacent column. Retain original format as 0.
3. If user inputs a number target value (eg 10), no action to take. Retain format as 0.

Private Sub Worksheet_Change(ByVal Target As Range)


Dim r1 As Range, r2 As Range

Application.EnableEvents = False

Set r1 = Target
Set r2 = Target.Offset(0, -1)

'calc delta using pct.. Only works if target is accounting format.. Why? 
If Right(r1.Text, 1) = "%" Then: _
r1 = r2 * r1

'set cell format so this works again
'This is the "accounting" format
r1.NumberFormat = _
"_(* #,##0.00_);_(* (#,##0.00);_(* " & """" & "-" & """" & "??_);_(@_)"

Application.EnableEvents = True

End Sub