How to select and print a text?

[vbdotnetxt]

I have a RichTextBox control on my form1. I have two strings called firstStr and secondStr.
firstStr = "(123456)"
secondStr = "(1234567890)"
I want to select 123456 from the secondStr.

This is how I wanted to do it and print it to the RichTextBox:

secondStr.Select(1,7)
RichTextBox.Text = secondStr.SelectedText

but it doesn't work

this doesn't work either:

secondStr.SelectionStart = 1
secondStr.SelectionLength = 7
RichTextBox.Text = secondStr.SelectedText

I want to eventually compare the selected text with firstStr.
How can I do that?

 

[barski]

bool isEqual=firstStr.Equals(secondStr.SubString(0,6));