Guys is there a better method of getting the cursor position?

This may be a real easy question but its eluding me........

I am writing a program that requires some Central European characters in the textbox. Setting the font to allow these is easy enough, even to mapping the keys on the keyboard with a keypress event triggering a change of ascii char with something like this in the keypress trigger.

If KeyAscii = 39 Then
TextPolish.Text = stringA + Chr$(185) + stringB: KeyAscii = 0
End If
where stringA is the left part of the string before the cursor and stringB is the right part after the cursor (if exists)

BUT> i am having an issue with textbox.selstart , if the user wants to alter the text and presses the back arrow then the text.selstart function returns its position +1 position. If the user deletes the whole word and starts again then its ok.
when the user starts typing again,

how can i get the cursor position as it is within the textbox?

another question

how do i set the cursor after the last character?

textbox.selstart= len(textbox.text)

The above is putting the cursor before the last character

Many thanks