C# Newbie help with regexp and files.

My company let go all the people with skill, and then dumped some 'simple' work on me, Only I have never done c#. I was the PC Tech.

I need to scan through a file and return the characters after a keyword, and before a paren. ex:
keyword whatINeed(

I would need to return WhatINeed.
in the file there will be many matches to the key word, and WhatINeed will be different most of the time.

I suspect I can use System.Text.RegularExpressions with the stream, but I'm not sure.

I am working with this string for this example:
keyword WhatINeed_A(foo, bar);keyword WhatINeed_B(foo, bar);


I have tried
@"keyword.*\("
but this returns:
keyword WhatINeed_A(foo, bar);keyword WhatINeed_B(


I really just need:
WhatINeed_A
WhatINeed_B

However, if the close as I can get is:
keyword WhatINeed_A(
keyword WhatINeed_B(

I could work wth that.