VBA Loop - Remove Single Character From Cell String Then Calculate New Value In Cell

I have a string of text in cell A2. In cell B2 of my spreadsheet is a formula that calculates a number based on the text string in cell A2.

I want to write a VBA loop that removes a single character from the cell A2 string, then calculate the new value in cell B2. I want this loop to continue until the value in B2 falls below a set value (in this case 60).

My code so far
Sub trim_text()
Dim mytext As String
Dim myanswer As Integer
mytext = Range("A2")
myanswer = Range("B2")
Do While myanswer > 60
mytext = (Right(mytext, Len(mytext) - 1))
Loop
End Sub

This obviously does not work. In my excel table I have a formula in cell B2 to calculate "myanswer" will this work, or does that code have to be placed into the VBA code?