Sometimes I paste text into a spreadsheet so that I can quickly manipulate it. The same could be done with a small script, but this particular feature is built into Open Office Spreadsheet: You can split text into separate columns using delimiters.
If I had text like this:
1. The Morning Breaks 2. The Spirit of God 3. Now Let Us Rejoice 4. Truth Eternal 5. High On A Mountain Top
I would paste it into one column in the spreadsheet, select that column, and select Date -> Text to Columns... In that dialog, you can select what you want to use as your delimiter. I my case, I chose the period ("."). That way, the hymn # ends up in column 1, the hymn title in column 2. The same feature is available in MS Excel.