I have numbers at the start of each line in my text file in the following format :
1: text written .... 2: text written ....
which continue
try this, it should work
^\d+(?:\.\d+)?%$
You can use this pattern:
^\d+\s:
If you can possibly have more than one space after it like this:
1 : 10 : 100 :
Use this pattern:
^\d+\s+:
Make sure you have Wrap around checked: