Stlyle on only one word

Create a character style and call it's 'Cap first letter' or something similar

so then you go to the paragraph style and insert the GREP code and apply the style

Style is Cap

code is 

\b(w)(?=ord\b)

for whatever word you want - you can replace it like tbps - I think you asked in another thread

so the code would be 

\b(t)(?=bps\b)

or if it's concrete

\b(c)(?=oncrete\b)

any word you want 

if you change the word - say in my example to 'words' or 'wording' then the w reduces back to lowercase, as it no longer matches the string.