Reg ex start with fixed string and end with varable number

I need to match these strings that start with fixed string These masters were created using and end with variable [space][name][space][char][number]

These masters were created using Kevin O014
These masters were created using Jhon A039
These masters were created using Geeth P034
These masters were created using Jemes M077
These masters were created using Ae H058
These masters were created using JANE S345

Any idea?

I tried this ^(These masters were created using).s.[a-zA-Z].s.[a-zA-Z].[0-9]{3}.$. it gooks greek to me

I would use this:

^These masters were created using [a-zA-Z]+ [a-zA-Z]d+$

See demo