Search for ^([^\s]*)(\s)
Replace with $1 AND_WHAT_EVER_STRING_YOU_WANT
Here is an example of searching for first space in a line and adding “',
” to the string

Search for ^([^\s]*)(\s)
Replace with $1 AND_WHAT_EVER_STRING_YOU_WANT
Here is an example of searching for first space in a line and adding “',
” to the string