Combo Box Based On Linked Table Needs To Pull Info For Sub-Form From Non Linked Table

I am trying to build a Form that will show an estimate (then eventually will be moved to a project if customer and employee aggree to price and project) in a Form F_Estimates is a M_Customers(Customer_ID) (Based on a Table) and thier info in a Subform. Also is the "projected costs" from parts out of the Parts(Part_ID) (Based on another Table) in a second Subform as a list that I need to calculate $$$ in
(Dang that still sounds evil and definately NOT understandable even after edit... so)

Here's some basic info

Tables

EstimatesandParts - Table
EstimatesandParts_ID : Autonumber
Estimate_ID : Number
Part_ID : Number

Parts - Table
Part_ID : Autonumber
PartNumber : Text (not a number due to some part#s have letters in them)
PartName : Text
Unit Price : Currency
Description : Text

Estimates - Table
Estimate_ID : Autonumber
InvoiceNumber : Text (again can have letters in it)
EstimateDate : Date/Time
EstimateTime : Date/Time
Employee_ID : Number
Customer_ID : Number
ProblemDescription : Memo

Customers - Table
Customer_ID : Autonumber
FirstName : Text
LastName : Text
CompanyName : Text
Address : Text
City : Text
Province_State : Text
Postal_ZIPCode : Text (CDN Postal codes are letter num letter...)

you can see the link table in the EstimatesandParts Table

Now I want to use that link to populate a subform in the F_Estimates form

Forms

SF_Customers - SubForm

(all boxes atm are text boxes on this form till I figure out the Parts section then will use same base for this so I can pick any customer in the database to be the customer for this estimate. Also will have ctrl button for making new customer with customer form and a refresh on Focus Gain bit of code)

FirstName
LastName
CompanyName
Address
City
Province_State
Postal_ZIPCode

SF_Parts - SubForm
Default View -Continuous Forms

(want it to be a list of parts that I can grab prices and descriptions from then in a bit of code to calculate a cost of parts)

Part_ID : Combo Box
Control Source - Part_ID
Row Source Type - Table/Query
Row Source - SELECT Parts.Part_ID, Parts.PartNumber, Parts.PartName, Parts.UnitPrice, Parts.Description FROM Parts ORDER BY Parts.Description;

(Pulls info from the table Parts for input into a list of parts to be used on that project)

PartName : Text Box
UnitPrice : Text Box

(here's where I run into problems due to the fact that the form is not based on the parts table but rather the link table EstimatesandParts so I can't propogate the info to the 2 other text boxes, ps I dont care if they cant be text boxes and have to be linked or some other type I'm not "set" just need to find out how to make it work )

(have tried a couple things to complete this task)

Me.txtPartName = Me.Part_ID.Column(2)
Me.txtUnitPrice = Me.Part_ID.Column(3)

(works AWSOME ... for ONE ROW then propogates the second selection to the first and second and third selection to first second and third and so on ...)

(tried to make control source for the txtPartName to)

=Forms!Parts!Partname

(Doesnt exist .. akkk, cant use ActiveForm either as it doesn't focus on the SubForm but the MainForm ... cry)

F_Estimates - Form

Estimate_ID
InvioceNumber
EstimateDate
EstimateTime
ProblemDescription

(all basic Text Boxes)

Employee_ID
Customer_ID

(Combo Boxes Select Customer and Employee from list of present ones of each)

SF_Customers
SF_Parts

(Both SubForms on the main form)

Now this is an Exerp from my entire Database I like to work on one small problem at a time and I have made this its own little database till I figure out the problem then I will bring the info I learn back into the rest of the database and go from there ...

Hope you can help I have a feeling I will need to make a recordset and go from there but I'm just not able to wrap my head around that for some reason

Thanks in advance for ANY and ALL help that I get from here