Hi Tim!

If you have the size of each line, you can sum this value until the line before of the line that error happening more the position of the line with the error and to use SelStart. Sample:

  * Error in line 3 position 10
  * Line 1, size 15
  * Line 2, size 20
  ThisForm.MyEdit.SelStart = 45

Is one experiment.
Bye!
Good Luck!