how to get a dash between words

i have title as---
Mayamma Ahiri
i wanted a dash between the words. i tried regular exp-replace matches with

field-title
regexp-(|) (\u)
matches with--$1 - $2
but it does not give the expected result.

i have another title---
Sri Mathrubhutham Kanada
i want a dash after the second word. how can i accomplish that?
thanks.

a dash before the last word:
$regexp(%title%,(.) (.),$1 - $2)

before the second last word:
$regexp(%title%,(.) (. .*),$1 - $2)

before the third last word:
$regexp(%title%,(.) (. .* .*),$1 - $2)

before the fourth last word:
$regexp(%title%,(.) (. .* .* .*),$1 - $2)

before the fifth last word:
$regexp(%title%,(.) (. .* .* .* .*),$1 - $2)

and so on...

after the first word:
$regexp(%title%,(.?) (.),$1 - $2)

after the second word:
$regexp(%title%,(.? .?) (.*),$1 - $2)

after the third word:
$regexp(%title%,(.? .? .?) (.),$1 - $2)

after the fourth word:
$regexp(%title%,(.? .? .? .?) (.*),$1 - $2)

after the fith word:
$regexp(%title%,(.? .? .? .? .?) (.),$1 - $2)

and so on...

if you want to use the regualar expression function as "stand alone" function, read the format strings above as: $regexp(field,regular expression,replace matches with)

alas! it works. have no words to express my gratitude. thank you PONE. have a nice day.