How can I expand a setting or variable in a vim regular expression?

Question

I have a regular expression, ^ \{3,}/, and want to use the value of a setting or variable in place of the 3. Here's the context:

match LeadingSpaces /^ \{3,}/
highlight LeadingSpaces ctermbg=red guibg=red

I'd like to use the value of tabstop in place of 3. Alternatively, I could set a new variable to be used.

Answer 1

Try the following instead of match LeadingSpaces /^ \{3,}/:

execute 'match LeadingSpaces /^ \{'.&tabstop.',}/'