Hi lifelongexpat,
Company administration is a big headache here, and it is expensive if you do not have your own people looking after it.
Assuming that you are an expat, and would like to be a shareholder in the company you would need to establish a foreign investment company (PT PMA, allowing foreign shareholders) They do not really do dormant companies here, so the company director is responsible for keeping the company compliant.
I used to hold a PT PMA, and I used it to contract my services as a consultant and own the apartment i lived in. As a one man show it really became a heavy burden, I have since divested the PT PMA and gone under a spouse sponsorship KITAP. I still haven't really cleared up my employment options and whether or not i need an IMTA to do what I do, so i stay home and look after the baby and let my wife work.

Here is what I learned about company administration. A reasonable guide on prices is
https://okusiassociates.com/services but I have never engaged them so I do not know anything about their services. Full respect to them for publishing everything transparently.
PT PMA (this is really really annoying now BKPM is clamping down on non-active companies)
- usually costs between 25 to 40 million to establish, adhere to negative investment list and show proof of funds (minimum 2.5 billion).
- takes anywhere between 3 - 6 months to complete.
- needs a minimum 2 shareholders which can also be the Director and Commissioner, if these are foreigners you would need KITAS and relevant IMTA (25 million per person per year, plus annual personal tax reporting).
- requirement to submit quarterly investment report (LKPM).
- must have a business domicile letter (surat domicili). requires an annually renewal (10 million per year for non active companies this could include the tax reporting)
- after a year, would need to convert the initial Principal Licence (Ijin Princip) to a Permanent Business Licence (IUT) this requires a mini audit and sign off from a chartered accountant. (6 to 10 million)
- most lodge monthly tax activity statement and do annual tax filing.
- need to lodge monthly BPJS kesehataan (health insurance) activity report (they assume that your Director is receiving a salary).
- need to pay annual BPJS ketenagakerjaan (workplace insurance)
if it is a Locally owned PT.
- Establishment could cost anywhere between 10 and 30 million need to show proof of funds available for the company (minimum about 50 million)
- 2 Indonesian KTP holders you trust. (Priceless)
- Domicile and Tax reporting (about the same as above, 10 million a year)
good luck