I heard this song about a decade ago in an Indian store in California and have travelled all over looking for it - does anyone know this hindi (Indian) song?

I've never heard a song like that but will keep an eye open for it. I found a shayari that might have been part of this song you're looking for:

chehraa kawal hai
baat ghazal hai
khushboo jaise chanchal hai
tera jism sang-e-marmar hai
tu ek zinda tajmahal hai

the song is from the 1986 movie Muddat.
its entitled "Pyar Hamara Amar Rahega".

beautiful song.... i first heard it on a visit to India in 1997, and fell in love with it immediately

You can watch the song here



Lyrics:

Pyar hamara amar rahega, yaad karega jahan
tu mumtaz hai mere khwabon ki
main tera shahey jahan, oh oh ah ah
pyar hamara amar rahega, yaad karega jahan
main mumtaz hoon tere khwabon ki
tu mera shahey jahan, oh oh ah ah

Chehera kamal hai, baaten ghazal hai
khushboo jaisi tu chanchal hai
tera badan hai sanghey mar mar
tu ik zinda taj mahal hai
utri hai tu aasman se, tujsa zameen pe kahan
oh oh ah ah
pyar hamara amar rahega, yaad karega jahan

Tu jo salamat, pyar salamat
teri bahen meri panha hain
tune humko itna chaha
aur khuda se hum kya chahey
naam wafa ka tujse hai zinda
tuj pe hai jaan qurbaan
oh oh ah ah
pyar hamara amar rahega, yaad karega jahan
tu mumtaz hai mere khwabon
tu mera shahey jahan
oh oh ah ah