Shell Programming and Scripting

Hello! I have a text file containing

some text : : : bla
other text : : : bla
any text : : : bla

containing 3 columns separated by the ':' sign.
Now i want to insert 'this' in the 2nd line after the 2nd column-deliminiter (i.e. into 3rd column), like

some text : : : bla
other text : : this : bla
any text : : : bla

How can this be done in a bash-script, usind sed or anything like that?
I want to be able to specify the place of insertion with variables, e.g.
$LINE and $COLUMN.
Someone with a solution?
knoxo

A way using awk :

Code:

awk 'BEGIN { FS=OFS=":" } NR==l { $f=v } 1' l=$LIGNE f=$COLUMN v=$VALUE input_file

Jean-Pierre.