Shower pump feed location

I'm looking to install a shower pump to improve water pressure at the head of the shower via a bath tap / pull up shower dual head. I understand its a positive head system. My question involves the location of the pump. The only space available is under the bath at the rear(opposite end to taps and drain). Hot water feed - the nearest 22mm hot water supply runs under the bath from the airing cupboard hot water tank. This is the feed out of the tank to the house. The cold however drops from the loft tank to the bathroom in 22mm and feeds the toilet, sink and bath first. Thus I would need to break into before the bath tap - extend to the pump and out to the bath/shower mixer. Is this possible? Many thanks..