i wish i was that cigaret... to go from your fingers to your lips....

My try:

Bu sigara olsam ... parmaklarýndan dudaklarýna gitmek için.

(Learner, corrections may be needed.)

 Just a little addition and a tiny correction to your try:

Keþke o sigara olsam...parmaklarýndan dudaklarýna gitmek için.

p.s. if s/he is smoking just beside you, you can use "bu".

sagol

Thanks Upsy for the correction.

Just wondering, is keþke necessary here? I thought it was a bit redundant if you used the -sa/-se suffix. Would keþke  be used for emphasis?

Thanks. 

Yes, keþke is necessary here.

The -se/-sa suffix has the same function as if-clause in English:

... olsaydým = if I were ...

When you place keþke before a verb suffixed by -se/-sa, it indicates an unfulfilled desire or a desire that cannot be fulfilled:

keþke ... olsaydým = I wish I were ...

O sigara olsaydým parmaklarýndan dudaklarýna giderdim=If I were that cigarette,I would go from your fingers to your lips.

keþke o sigara olsaydým...parmaklarýndan dudaklarýna gitmek için=I wish I were that cigarette... to go from your fingers to your lips.

I see keþke a bit like saying

If only

 if only is more like saying ah! bir than keþke even if they are often interchangeable:

Ah! bir gelebilse! = if he could only come!

Ah! bir zamanýnda yetiþse! = if only he arrives in time!

Ah! bir onu görebilmiþ olsaydýn. =if only you could have seen it.