I want to estimate an equation by setting restrictions to coefficients. Likewise, I want to get common coefficients of some variables. My equation looks like :

depvar = c1 (ni_star + prem)+(1-c1)*(c2*ni(-1)+(1-c2)*(ni_neutral + c3*(dot4_cpi(+1) - inflation_ss_star(+1))) + c4*lgdp_gap)

where 0<c1, c2, c3<1. Can I estimate the common coefficients c1, c2 and c3 if the condition 0<c1, c2, c3<1. is met?

I know that I need to run a structural model. I tried to go through structural equation modelling but was unable to get the common coefficients.

Many thanks