Capitalize first letter in PHP using RegEx?

[Denitu]

I have data in a notepad file as following:\[code\]A 1-6A 1-7B 1-8B 1-9B 1-10c 1-11C 1-12D 1-13F 1-14F 1-15f 1-16\[/code\]I want above data to be updated as below in the notepad file:\[code\]<strong>A</strong> 1-6A 1-7<strong>B</strong> 1-8B 1-9B 1-10<strong>c</strong> 1-11C 1-12<strong>D</strong> 1-13<strong>F</strong> 1-14F 1-15f 1-16\[/code\]Which means adding a \[code\]<strong>\[/code\] tag or any other tag with first character alphabetically. The data in file is sorted alphabetically (A to Z).I want to achieve this in PHP using RegEx techniques, please help!Thanks.