Regex replace between notepad++

Question

I have a list of values in a csv, which i'm trying to alter slightly using a REGEX search and replace using Notepad++. What I have contains the following examples:

Text,UK_BT.BT1.BT1 1,123
Text,UK_BT.BT11.BT11 1,123
Text,IE_text.text.text,123

What i'm wanting to do, is remove the text between first comma and last period, only where the line contains UK_BT. So the output would be:

Text,BT1 1,123
Text,BT11 1,123
Text,IE_text.text.text,123

Does anyone have any clues? Regex really isnt my strongpoint and generally gets forgotten after using it! Thanks,

Answer 1

Find what: ^(?=.*UK_BT.*)([^,]+,).*\.([^\.]+)$

Replace with \1\2

Explanation

^             # Beginning of the line.
(?=.*UK_BT.*) # Must contain 'UK_BT' (positive look ahead, not capturing group, not character consuming).
(             # Beginning of the first group.
  [^,]+,      # Everything but ',' at least one time (+) followed by ',' (first ',').
)             # End of the first group.
.*            # Everything zero or more times.
\.            # A single '.'.
(             # Beginning of the second group.
 [^\.]+       # Everything but '.' at least one time (this in combination with '\.' allows to find the last '.').
)             # End of the second group.
$             # End of the line

\1\2 allows to point to the first and second captured group.