oh ok thaks
only way to replace a section in the line is by reading that line first, setting it to a variable, replacing what you want in that variable, and then writing that back over the line.
example:
alias txtrepex {
var %filename $?="Please enter the directory to the file in which you want to replace"
var %linetoreplace $?="Please enter the line number in which you want to replace"
var %readingline $read(%filename,%linetoreplace)
var %toreplace $?="What would you like to replace in the line"
var %afterreplace $?="and the replacement is"
var %enterline $replace(%readingline,%toreplace,%afterreplace)
/write %filename -l $+ %linetoreplace %enterline
}
this example is very basic, and can be done in a lot less lines if you know what you are doing. try and read through this, and see how it works.